{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T17:09:34Z","timestamp":1774717774820,"version":"3.50.1"},"reference-count":63,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2024,3,10]],"date-time":"2024-03-10T00:00:00Z","timestamp":1710028800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2024,3,10]],"date-time":"2024-03-10T00:00:00Z","timestamp":1710028800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["SCHO 1140\/8-2"],"award-info":[{"award-number":["SCHO 1140\/8-2"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006360","name":"Bundesministerium f\u00fcr Wirtschaft und Energie","doi-asserted-by":"publisher","award":["01MK20013A"],"award-info":[{"award-number":["01MK20013A"]}],"id":[{"id":"10.13039\/501100006360","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Rheinland-Pf\u00e4lzische Technische Universit\u00e4t Kaiserslautern-Landau"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["OR Spectrum"],"published-print":{"date-parts":[[2024,6]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>In this paper, we introduce a last-mile delivery concept that is well suited for urban areas. By jointly optimizing the tour of a truck and a cargo bike, we ensure that each vehicle is used optimally. Here, we assume that the bike is restocked by meeting up with the truck so that no dedicated mini-hubs have to be constructed. We model different objective functions and analyze the different variants in comparison to the traveling salesperson problem as well as the capacitated vehicle routing problem. In an experimental evaluation, we compare MIP formulations for different problem variants and assess several heuristic approaches to solve large-scale instances. These results show that we can outperform the truck-only delivery in terms of completion time while reducing the distance driven by the truck.\n<\/jats:p>","DOI":"10.1007\/s00291-024-00754-2","type":"journal-article","created":{"date-parts":[[2024,3,10]],"date-time":"2024-03-10T17:01:53Z","timestamp":1710090113000},"page":"545-587","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Optimizing combined tours: The truck-and-cargo-bike case"],"prefix":"10.1007","volume":"46","author":[{"given":"Philine","family":"Schiewe","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7940-5291","authenticated-orcid":false,"given":"Moritz","family":"Stinzend\u00f6rfer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2024,3,10]]},"reference":[{"issue":"4","key":"754_CR1","doi-asserted-by":"publisher","first-page":"965","DOI":"10.1287\/trsc.2017.0791","volume":"52","author":"N Agatz","year":"2018","unstructured":"Agatz N, Bouman P, Schmidt M (2018) Optimization approaches for the traveling salesman problem with drone. Transp Sci 52(4):965\u2013981","journal-title":"Transp Sci"},{"issue":"2","key":"754_CR2","doi-asserted-by":"publisher","first-page":"107","DOI":"10.3233\/MGS-150232","volume":"11","author":"MM Alipour","year":"2015","unstructured":"Alipour MM, Razavi SN (2015) A new multiagent reinforcement learning algorithm to solve the symmetric traveling salesman problem. Multiagent Grid Syst 11(2):107\u2013119","journal-title":"Multiagent Grid Syst"},{"key":"754_CR3","doi-asserted-by":"crossref","unstructured":"Amorosi L, Puerto J, Valverde C (2021) Coordinating drones with mothership vehicles: the mothership and multiple drones routing problem with graphs. arXiv preprint arXiv:2109.01447","DOI":"10.1016\/j.cor.2021.105445"},{"key":"754_CR4","doi-asserted-by":"publisher","first-page":"101","DOI":"10.1016\/j.sbspro.2012.03.094","volume":"39","author":"N Anand","year":"2012","unstructured":"Anand N, Quak H, van Duin R, Tavasszy L (2012) City logistics modeling efforts: trends and gaps\u2014a review. Procedia Soc Behav Sci 39:101\u2013115","journal-title":"Procedia Soc Behav Sci"},{"issue":"2","key":"754_CR5","doi-asserted-by":"publisher","first-page":"345","DOI":"10.1007\/s10100-016-0441-z","volume":"25","author":"A Anderluh","year":"2017","unstructured":"Anderluh A, Hemmelmayr VC, Nolz PC (2017) Synchronizing vans and cargo bikes in a city distribution network. CEJOR 25(2):345\u2013376","journal-title":"CEJOR"},{"issue":"3","key":"754_CR6","doi-asserted-by":"publisher","first-page":"940","DOI":"10.1016\/j.ejor.2019.07.049","volume":"289","author":"A Anderluh","year":"2021","unstructured":"Anderluh A, Nolz PC, Hemmelmayr VC, Crainic TG (2021) Multi-objective optimization of a two-echelon vehicle routing problem with vehicle synchronization and grey zone\u2019customers arising in urban logistics. Eur J Oper Res 289(3):940\u2013958","journal-title":"Eur J Oper Res"},{"key":"754_CR7","unstructured":"Applegate DL, Bixby RE, Chv\u00e1tal V, Cook WJ (2011) The traveling salesman problem: a computational study. Princeton University Press"},{"key":"754_CR8","unstructured":"Augerat P (1995) Approche poly\u00e8drale du probl\u00e8me de tourn\u00e9es de v\u00e9hicules. PhD thesis, Institut National Polytechnique de Grenoble-INPG"},{"key":"754_CR9","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1007\/978-0-387-77778-8_1","volume-title":"The vehicle routing problem: latest advances and new challenges","author":"R Baldacci","year":"2008","unstructured":"Baldacci R, Battarra M, Vigo D (2008) Routing a heterogeneous fleet of vehicles. The vehicle routing problem: latest advances and new challenges. Springer, US, Boston, MA, pp 3\u201327"},{"key":"754_CR10","unstructured":"Bektas T, Crainic TG, Van Woensel T (2015) From managing urban freight to smart city logistics networks, Project report"},{"issue":"1","key":"754_CR11","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/s11750-007-0009-0","volume":"15","author":"G Berbeglia","year":"2007","unstructured":"Berbeglia G, Cordeau J-F, Gribkovskaia I, Laporte G (2007) Static pickup and delivery problems: a classification scheme and survey. TOP 15(1):1\u201331","journal-title":"TOP"},{"issue":"3","key":"754_CR12","doi-asserted-by":"publisher","first-page":"574","DOI":"10.1287\/opre.40.3.574","volume":"40","author":"DJ Bertsimas","year":"1992","unstructured":"Bertsimas DJ (1992) A vehicle routing problem with stochastic demand. Oper Res 40(3):574\u2013585","journal-title":"Oper Res"},{"key":"754_CR13","doi-asserted-by":"publisher","first-page":"126","DOI":"10.1016\/j.compenvurbsys.2017.05.004","volume":"65","author":"G Boeing","year":"2017","unstructured":"Boeing G (2017) Osmnx: new methods for acquiring, constructing, analyzing, and visualizing complex street networks. Comput Environ Urban Syst 65:126\u2013139","journal-title":"Comput Environ Urban Syst"},{"key":"754_CR14","doi-asserted-by":"publisher","DOI":"10.1016\/j.trc.2022.103981","volume":"148","author":"A Bogyrbayeva","year":"2023","unstructured":"Bogyrbayeva A, Yoon T, Ko H, Lim S, Yun H, Kwon C (2023) A deep reinforcement learning approach for solving the traveling salesman problem with drone. Transp Res Part C: Emerg Technol 148:103981","journal-title":"Transp Res Part C: Emerg Technol"},{"issue":"4","key":"754_CR15","doi-asserted-by":"publisher","first-page":"528","DOI":"10.1002\/net.21864","volume":"72","author":"P Bouman","year":"2018","unstructured":"Bouman P, Agatz N, Schmidt M (2018) Dynamic programming approaches for the traveling salesman problem with drone. Networks 72(4):528\u2013542","journal-title":"Networks"},{"key":"754_CR16","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/s00291-020-00607-8","volume":"43","author":"N Boysen","year":"2021","unstructured":"Boysen N, Fedtke S, Schwerdfeger S (2021) Last-mile delivery concepts: a survey from an operational research perspective. OR Spectrum 43:1\u201358","journal-title":"OR Spectrum"},{"issue":"4","key":"754_CR17","doi-asserted-by":"publisher","first-page":"506","DOI":"10.1002\/net.21847","volume":"72","author":"N Boysen","year":"2018","unstructured":"Boysen N, Briskorn D, Fedtke S, Schwerdfeger S (2018) Drone delivery from trucks: drone scheduling for given truck routes. Networks 72(4):506\u2013527","journal-title":"Networks"},{"key":"754_CR18","first-page":"183","volume":"1","author":"L Bu\u015foniu","year":"2010","unstructured":"Bu\u015foniu L, Babu\u0161ka R, Schutter BD (2010) Multi-agent reinforcement learning: an overview. Innov Multi-agent Syst Appl 1:183\u2013221","journal-title":"Innov Multi-agent Syst Appl"},{"issue":"1","key":"754_CR19","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1016\/S0305-0548(00)00056-3","volume":"29","author":"I-M Chao","year":"2002","unstructured":"Chao I-M (2002) A tabu search method for the truck and trailer routing problem. Comput Oper Res 29(1):33\u201351","journal-title":"Comput Oper Res"},{"issue":"4","key":"754_CR20","doi-asserted-by":"publisher","first-page":"568","DOI":"10.1287\/opre.12.4.568","volume":"12","author":"G Clarke","year":"1964","unstructured":"Clarke G, Wright JW (1964) Scheduling of vehicles from a central depot to a number of delivery points. Oper Res 12(4):568\u2013581","journal-title":"Oper Res"},{"issue":"12","key":"754_CR21","doi-asserted-by":"publisher","first-page":"3185","DOI":"10.1016\/j.cor.2012.04.003","volume":"39","author":"C Contardo","year":"2012","unstructured":"Contardo C, Hemmelmayr V, Crainic TG (2012) Lower and upper bounds for the two-echelon capacitated location-routing problem. Comput Oper Res 39(12):3185\u20133199","journal-title":"Comput Oper Res"},{"key":"754_CR22","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1016\/j.procs.2019.09.158","volume":"159","author":"GC Cri\u015fan","year":"2019","unstructured":"Cri\u015fan GC, Nechita E (2019) On a cooperative truck-and-drone delivery system. Proced Comput Sci 159:38\u201347","journal-title":"Proced Comput Sci"},{"key":"754_CR23","doi-asserted-by":"publisher","first-page":"185","DOI":"10.1016\/j.cor.2014.06.008","volume":"55","author":"R Cuda","year":"2015","unstructured":"Cuda R, Guastaroba G, Speranza MG (2015) A survey on two-echelon routing problems. Comput Oper Res 55:185\u2013199","journal-title":"Comput Oper Res"},{"issue":"2","key":"754_CR24","doi-asserted-by":"publisher","first-page":"342","DOI":"10.1287\/opre.40.2.342","volume":"40","author":"M Desrochers","year":"1992","unstructured":"Desrochers M, Desrosiers J, Solomon M (1992) A new optimization algorithm for the vehicle routing problem with time windows. Oper Res 40(2):342\u2013354","journal-title":"Oper Res"},{"issue":"3","key":"754_CR25","doi-asserted-by":"publisher","first-page":"297","DOI":"10.1287\/trsc.1110.0400","volume":"46","author":"M Drexl","year":"2012","unstructured":"Drexl M (2012) Synchronization in vehicle routing-a survey of VRPS with multiple synchronization constraints. Transp Sci 46(3):297\u2013316","journal-title":"Transp Sci"},{"issue":"2","key":"754_CR26","doi-asserted-by":"publisher","first-page":"275","DOI":"10.1016\/j.ejor.2012.12.015","volume":"227","author":"M Drexl","year":"2013","unstructured":"Drexl M (2013) Applications of the vehicle routing problem with trailers and transshipments. Eur J Oper Res 227(2):275\u2013283","journal-title":"Eur J Oper Res"},{"issue":"3","key":"754_CR27","doi-asserted-by":"publisher","first-page":"383","DOI":"10.1002\/nav.3800370304","volume":"37","author":"M Dror","year":"1990","unstructured":"Dror M, Trudeau P (1990) Split delivery routing. Naval Res Log (NRL) 37(3):383\u2013402","journal-title":"Naval Res Log (NRL)"},{"key":"754_CR28","doi-asserted-by":"crossref","unstructured":"Gambardella LM, Dorigo M (1995) Ant-q: a reinforcement learning approach to the traveling salesman problem. In: Machine learning proceedings. Elsevier, pp 252\u2013260","DOI":"10.1016\/B978-1-55860-377-6.50039-6"},{"issue":"2","key":"754_CR29","doi-asserted-by":"publisher","first-page":"143","DOI":"10.1287\/trsc.29.2.143","volume":"29","author":"M Gendreau","year":"1995","unstructured":"Gendreau M, Laporte G, S\u00e9guin R (1995) An exact algorithm for the vehicle routing problem with stochastic demands and customers. Transp Sci 29(2):143\u2013155","journal-title":"Transp Sci"},{"issue":"2","key":"754_CR30","first-page":"147","volume":"54","author":"V Ghilas","year":"2016","unstructured":"Ghilas V, Demir E, Van Woensel T (2016) The pickup and delivery problem with time windows and scheduled lines. INFOR: Inf Syst Oper Res 54(2):147\u2013167","journal-title":"INFOR: Inf Syst Oper Res"},{"issue":"1","key":"754_CR31","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1016\/0377-2217(89)90057-X","volume":"42","author":"M Goetschalckx","year":"1989","unstructured":"Goetschalckx M, Jacobs-Blecha C (1989) The vehicle routing problem with backhauls. Eur J Oper Res 42(1):39\u201351","journal-title":"Eur J Oper Res"},{"key":"754_CR32","unstructured":"Gonzalez-Feliu J, Perboli G, Tadei R, Vigo D (2008) The two-echelon capacitated vehicle routing problem, working paper or preprint"},{"issue":"1","key":"754_CR33","doi-asserted-by":"publisher","first-page":"80","DOI":"10.1016\/j.ejor.2016.03.040","volume":"254","author":"P Grangier","year":"2016","unstructured":"Grangier P, Gendreau M, Lehu\u00e9d\u00e9 F, Rousseau L-M (2016) An adaptive large neighborhood search for the two-echelon multiple-trip vehicle routing problem with satellite synchronization. Eur J Oper Res 254(1):80\u201391","journal-title":"Eur J Oper Res"},{"key":"754_CR34","unstructured":"Gurobi Optimizer (2019) Gurobi optimizer version 8.1.1. Gurobi Optimization, Inc., Houston. http:\/\/www.gurobi.com\/"},{"issue":"12","key":"754_CR35","doi-asserted-by":"publisher","first-page":"3215","DOI":"10.1016\/j.cor.2012.04.007","volume":"39","author":"VC Hemmelmayr","year":"2012","unstructured":"Hemmelmayr VC, Cordeau J-F, Crainic TG (2012) An adaptive large neighborhood search heuristic for two-echelon vehicle routing problems arising in city logistics. Comput Oper Res 39(12):3215\u20133228","journal-title":"Comput Oper Res"},{"key":"754_CR36","doi-asserted-by":"crossref","unstructured":"J\u00fcnger M, Reinelt G, Rinaldi G (1995) Chapter 4 the traveling salesman problem. In: Network models, volume\u00a07 of handbooks in operations research and management science. Elsevier, pp 225\u2013330","DOI":"10.1016\/S0927-0507(05)80121-5"},{"key":"754_CR37","unstructured":"J\u00fanior FCDL, Neto ADD, De Melo JD (2010) Hybrid metaheuristics using reinforcement learning applied to salesman traveling problem. In: Traveling salesman problem, theory and applications. IntechOpen"},{"issue":"2","key":"754_CR38","doi-asserted-by":"publisher","first-page":"231","DOI":"10.1016\/0377-2217(92)90138-Y","volume":"59","author":"G Laporte","year":"1992","unstructured":"Laporte G (1992) The traveling salesman problem: an overview of exact and approximate algorithms. Eur J Oper Res 59(2):231\u2013247","journal-title":"Eur J Oper Res"},{"issue":"3","key":"754_CR39","doi-asserted-by":"publisher","first-page":"161","DOI":"10.1287\/trsc.26.3.161","volume":"26","author":"G Laporte","year":"1992","unstructured":"Laporte G, Louveaux F, Mercure H (1992) The vehicle routing problem with stochastic travel times. Transp Sci 26(3):161\u2013170","journal-title":"Transp Sci"},{"key":"754_CR40","doi-asserted-by":"crossref","unstructured":"Li H, Zhao J, Zhan Z (2022) Truck and unmanned vehicle routing problem with time windows: a satellite synchronization perspective. J Adv Transport","DOI":"10.1155\/2022\/6599089"},{"issue":"3","key":"754_CR41","doi-asserted-by":"publisher","first-page":"775","DOI":"10.1016\/j.ejor.2020.06.019","volume":"288","author":"H Li","year":"2021","unstructured":"Li H, Wang H, Chen J, Bai M (2021) Two-echelon vehicle routing problem with satellite bi-synchronization. Eur J Oper Res 288(3):775\u2013793","journal-title":"Eur J Oper Res"},{"issue":"12","key":"754_CR42","doi-asserted-by":"publisher","first-page":"15244","DOI":"10.1016\/j.eswa.2011.05.075","volume":"38","author":"S-W Lin","year":"2011","unstructured":"Lin S-W, Vincent FY, Lu C-C (2011) A simulated annealing heuristic for the truck and trailer routing problem with time windows. Expert Syst Appl 38(12):15244\u201315252","journal-title":"Expert Syst Appl"},{"issue":"12","key":"754_CR43","doi-asserted-by":"publisher","first-page":"7450","DOI":"10.1109\/TSMC.2020.2968839","volume":"51","author":"Y Liu","year":"2020","unstructured":"Liu Y, Liu Z, Shi J, Wu G, Pedrycz W (2020) Two-echelon routing problem for parcel delivery by cooperated truck and drone. IEEE Trans Syst, Man, Cybern: Syst 51(12):7450\u20137465","journal-title":"IEEE Trans Syst, Man, Cybern: Syst"},{"issue":"3","key":"754_CR44","doi-asserted-by":"publisher","first-page":"185","DOI":"10.1287\/trsc.26.3.185","volume":"26","author":"C Malandraki","year":"1992","unstructured":"Malandraki C, Daskin MS (1992) Time dependent vehicle routing problems: formulations, properties and heuristic algorithms. Transp Sci 26(3):185\u2013200","journal-title":"Transp Sci"},{"issue":"4","key":"754_CR45","doi-asserted-by":"publisher","first-page":"326","DOI":"10.1145\/321043.321046","volume":"7","author":"CE Miller","year":"1960","unstructured":"Miller CE, Tucker AW, Zemlin RA (1960) Integer programming formulation of traveling salesman problems. J ACM 7(4):326\u2013329","journal-title":"J ACM"},{"key":"754_CR46","doi-asserted-by":"publisher","first-page":"86","DOI":"10.1016\/j.trc.2015.03.005","volume":"54","author":"CC Murray","year":"2015","unstructured":"Murray CC, Chu AG (2015) The flying sidekick traveling salesman problem: optimization of drone-assisted parcel delivery. Transp Res Part C: Emerg Technol 54:86\u2013109","journal-title":"Transp Res Part C: Emerg Technol"},{"key":"754_CR47","doi-asserted-by":"crossref","unstructured":"Nguyen MA, H\u00e0 MH (2023) The parallel drone scheduling traveling salesman problem with collective drones. Transport Sci","DOI":"10.1287\/trsc.2022.1192"},{"issue":"1","key":"754_CR48","doi-asserted-by":"publisher","first-page":"113","DOI":"10.1016\/j.ejor.2011.07.030","volume":"216","author":"V-P Nguyen","year":"2012","unstructured":"Nguyen V-P, Prins C, Prodhon C (2012) Solving the two-echelon location routing problem by a grasp reinforced by a learning process and path relinking. Eur J Oper Res 216(1):113\u2013126","journal-title":"Eur J Oper Res"},{"key":"754_CR49","unstructured":"OpenStreetMap contributors (2017) Planet dump retrieved from https:\/\/www.openstreetmap.org"},{"issue":"3","key":"754_CR50","doi-asserted-by":"publisher","first-page":"364","DOI":"10.1287\/trsc.1110.0368","volume":"45","author":"G Perboli","year":"2011","unstructured":"Perboli G, Tadei R, Vigo D (2011) The two-echelon capacitated vehicle routing problem: models and math-based heuristics. Transp Sci 45(3):364\u2013380","journal-title":"Transp Sci"},{"issue":"4","key":"754_CR51","doi-asserted-by":"publisher","first-page":"1439","DOI":"10.3390\/su12041439","volume":"12","author":"F Russo","year":"2020","unstructured":"Russo F, Comi A (2020) Investigating the effects of city logistics measures on the economy of the city. Sustainability 12(4):1439","journal-title":"Sustainability"},{"issue":"2","key":"754_CR52","doi-asserted-by":"publisher","first-page":"164","DOI":"10.1002\/net.21958","volume":"76","author":"D Schermer","year":"2020","unstructured":"Schermer D, Moeini M, Wendt O (2020) A b ranch-and-cut approach and alternative formulations for the traveling salesman problem with drone. Networks 76(2):164\u2013186","journal-title":"Networks"},{"issue":"3","key":"754_CR53","doi-asserted-by":"publisher","first-page":"865","DOI":"10.1016\/j.ejor.2022.02.022","volume":"304","author":"N Sluijk","year":"2023","unstructured":"Sluijk N, Florio AM, Kinable J, Dellaert N, Van Woensel T (2023) Two-echelon vehicle routing problems: a literature review. Eur J Oper Res 304(3):865\u2013886","journal-title":"Eur J Oper Res"},{"key":"754_CR54","unstructured":"Stinzend\u00f6rfer M, Schiewe P (2024) Supplementary material for publication \u201coptimizing combined tours\u2014the truck-and-cargo-bike case\u201d. https:\/\/doi.org\/10.5281\/zenodo.10591544"},{"issue":"1\u20132","key":"754_CR55","doi-asserted-by":"publisher","first-page":"203","DOI":"10.1007\/s10479-023-05177-w","volume":"323","author":"H Sutrisno","year":"2023","unstructured":"Sutrisno H, Yang C-L (2023) A two-echelon location routing problem with mobile satellites for last-mile delivery: mathematical formulation and clustering-based heuristic method. Ann Oper Res 323(1\u20132):203\u2013228","journal-title":"Ann Oper Res"},{"key":"754_CR56","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1016\/j.trpro.2020.03.157","volume":"46","author":"E Taniguchi","year":"2020","unstructured":"Taniguchi E, Thompson RG, Qureshi AG (2020) Modelling city logistics using recent innovative technologies. Transp Res Proced 46:3\u201312","journal-title":"Transp Res Proced"},{"issue":"1","key":"754_CR57","doi-asserted-by":"publisher","first-page":"529","DOI":"10.3390\/app12010529","volume":"12","author":"B Tong","year":"2022","unstructured":"Tong B, Wang J, Wang X, Zhou F, Mao X, Zheng W (2022) Optimal route planning for truck-drone delivery using variable neighborhood tabu search algorithm. Appl Sci 12(1):529","journal-title":"Appl Sci"},{"key":"754_CR58","doi-asserted-by":"crossref","unstructured":"Toth P, Vigo D (2014) Vehicle routing: problems, methods, and applications. SIAM","DOI":"10.1137\/1.9781611973594"},{"issue":"5","key":"754_CR59","doi-asserted-by":"publisher","first-page":"2968","DOI":"10.1111\/itor.13052","volume":"29","author":"L Vu","year":"2022","unstructured":"Vu L, Vu DM, H\u00e0 MH, Nguyen V-P (2022) The two-echelon routing problem with truck and drones. Int Trans Oper Res 29(5):2968\u20132994","journal-title":"Int Trans Oper Res"},{"key":"754_CR60","doi-asserted-by":"publisher","first-page":"1708","DOI":"10.1057\/jors.2008.108","volume":"60","author":"M Wen","year":"2009","unstructured":"Wen M, Larsen J, Clausen J, Cordeau J-F, Laporte G (2009) Vehicle routing with cross-docking. J Oper Res Soc 60:1708\u20131718","journal-title":"J Oper Res Soc"},{"issue":"2","key":"754_CR61","doi-asserted-by":"publisher","first-page":"980","DOI":"10.1016\/j.ijpe.2007.11.011","volume":"113","author":"G Z\u00e4pfel","year":"2008","unstructured":"Z\u00e4pfel G, B\u00f6gl M (2008) Multi-period vehicle routing and crew scheduling with outsourcing options. Int J Prod Econ 113(2):980\u2013996","journal-title":"Int J Prod Econ"},{"key":"754_CR62","doi-asserted-by":"crossref","unstructured":"Zhang R, Prokhorchuk A, Dauwels J (2020) Deep reinforcement learning for traveling salesman problem with time windows and rejections. In: 2020 international joint conference on neural networks (IJCNN). IEEE, pp 1\u20138","DOI":"10.1109\/IJCNN48605.2020.9207026"},{"key":"754_CR63","doi-asserted-by":"publisher","first-page":"124","DOI":"10.1016\/j.trb.2023.01.002","volume":"168","author":"H Zhou","year":"2023","unstructured":"Zhou H, Qin H, Cheng C, Rousseau L-M (2023) An exact algorithm for the two-echelon vehicle routing problem with drones. Transp Res Part B: Methodol 168:124\u2013150","journal-title":"Transp Res Part B: Methodol"}],"container-title":["OR Spectrum"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00291-024-00754-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s00291-024-00754-2\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00291-024-00754-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,1]],"date-time":"2024-06-01T17:01:51Z","timestamp":1717261311000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s00291-024-00754-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,3,10]]},"references-count":63,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2024,6]]}},"alternative-id":["754"],"URL":"https:\/\/doi.org\/10.1007\/s00291-024-00754-2","relation":{},"ISSN":["0171-6468","1436-6304"],"issn-type":[{"value":"0171-6468","type":"print"},{"value":"1436-6304","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,3,10]]},"assertion":[{"value":"25 August 2023","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 February 2024","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 March 2024","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}}]}}