{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,19]],"date-time":"2026-01-19T09:03:36Z","timestamp":1768813416872,"version":"3.49.0"},"reference-count":57,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2021,8,24]],"date-time":"2021-08-24T00:00:00Z","timestamp":1629763200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish ministry of Science, Innovation and Universities","award":["PTQ-17-09404"],"award-info":[{"award-number":["PTQ-17-09404"]}]},{"DOI":"10.13039\/100012818","name":"Comunidad de Madrid","doi-asserted-by":"publisher","award":["P2018\/EMT-4338"],"award-info":[{"award-number":["P2018\/EMT-4338"]}],"id":[{"id":"10.13039\/100012818","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Conducting topographic surveys in active mines is challenging due ongoing operations and hazards, particularly in highwalls subject to constant and active mass movements (rock and earth falls, slides and flows). These vertical and long surfaces are the core of most mines, as the mineral feeding mining production originates there. They often lack easy and safe access paths. This framework highlights the importance of accomplishing non-contact high-accuracy and detailed topographies to detect instabilities prior to their occurrence. We have conducted drone flights in search of the best settings in terms of altitude mode and camera angle, to produce digital representation of topographies using Structure from Motion. Identification of discontinuities was evaluated, as they are a reliable indicator of potential failure areas. Natural shapes were used as control\/check points and were surveyed using a robotic total station with a coaxial camera. The study was conducted in an active kaolin mine near the Alto Tajo Natural Park of East-Central Spain. Here the 140 m highwall is formed by layers of limestone, marls and sands. We demonstrate that for this vertical landscape, a facade drone flight mode combined with a nadir camera angle, and automatically programmed with a computer-based mission planning software, provides the most accurate and detailed topographies, in the shortest time and with increased flight safety. Contrary to previous reports, adding oblique images does not improve accuracy for this configuration. Moreover, neither extra sets of images nor an expert pilot are required. These topographies allowed the detection of 93.5% more discontinuities than the Above Mean Sea Level surveys, the common approach used in mining areas. Our findings improve the present SfM-UAV survey workflows in long highwalls. The versatile topographies are useful for the management and stabilization of highwalls during phases of operation, as well closure-reclamation.<\/jats:p>","DOI":"10.3390\/rs13173353","type":"journal-article","created":{"date-parts":[[2021,8,24]],"date-time":"2021-08-24T22:09:39Z","timestamp":1629842979000},"page":"3353","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Improvement of Workflow for Topographic Surveys in Long Highwalls of Open Pit Mines with an Unmanned Aerial Vehicle and Structure from Motion"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7454-169X","authenticated-orcid":false,"given":"Ignacio","family":"Zapico","sequence":"first","affiliation":[{"name":"Geodynamics, Stratigraphy and Paleontology Department, Complutense University, 28040 Madrid, Spain"},{"name":"Instituto de Geociencias, IGEO (CSIC, UCM), 28040 Madrid, Spain"}]},{"given":"Jonathan B.","family":"Laronne","sequence":"additional","affiliation":[{"name":"Department of Geography and Environmental Development, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel"}]},{"given":"L\u00e1zaro","family":"S\u00e1nchez Castillo","sequence":"additional","affiliation":[{"name":"Department of Mining and Geologic Engineering, Polytechnic University of Madrid, 28003 Madrid, Spain"}]},{"given":"Jos\u00e9 F.","family":"Mart\u00edn Duque","sequence":"additional","affiliation":[{"name":"Geodynamics, Stratigraphy and Paleontology Department, Complutense University, 28040 Madrid, Spain"},{"name":"Instituto de Geociencias, IGEO (CSIC, UCM), 28040 Madrid, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,24]]},"reference":[{"key":"ref_1","unstructured":"Shroder, J.F. (2013). 13.6 Impacts of mining on geomorphic systems. Treatise on Geomorphology, Academic Press."},{"key":"ref_2","first-page":"76","article-title":"Open-Pit Mining Geomorphic Feature Characterisation","volume":"42","author":"Chen","year":"2015","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.ecoleng.2017.11.011","article-title":"Geomorphic Reclamation for Reestablishment of Landform Stability at a Watershed Scale in Mined Sites: The Alto Tajo Natural Park, Spain","volume":"111","author":"Zapico","year":"2018","journal-title":"Ecol. Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"110717","DOI":"10.1016\/j.jenvman.2020.110717","article-title":"Unmanned Aerial System Protocol for Quarry Restoration and Mineral Extraction Monitoring","volume":"270","author":"Carabassa","year":"2020","journal-title":"J. Environ. Manag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"105321","DOI":"10.1016\/j.enggeo.2019.105321","article-title":"Stabilization by Geomorphic Reclamation of a Rotational Landslide in an Abandoned Mine next to the Alto Tajo Natural Park","volume":"264","author":"Zapico","year":"2020","journal-title":"Eng. Geol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10064-020-01766-2","article-title":"The Use of Unmanned Aerial Vehicles (UAVs) for Engineering Geology Applications","volume":"79","author":"Giordan","year":"2020","journal-title":"Bull. Eng. Geol. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/B978-0-444-64177-9.00001-1","article-title":"Structure from Motion Photogrammetric Technique","volume":"23","author":"Eltner","year":"2020","journal-title":"Dev. Earth Surf. Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1826","DOI":"10.1007\/s11629-020-6064-9","article-title":"Multitemporal UAV-Based Photogrammetry for Landslide Detection and Monitoring in a Large Area: A Case Study in the Heifangtai Terrace in the Loess Plateau of China","volume":"17","author":"Xu","year":"2020","journal-title":"J. Mt. Sci."},{"key":"ref_9","first-page":"163","article-title":"Multi-Temporal UAV Based Repeat Monitoring of Rivers Sensitive to Flood","volume":"17","year":"2020","journal-title":"J. Maps"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.geomorph.2016.12.003","article-title":"Can DEM Time Series Produced by UAV Be Used to Quantify Diffuse Erosion in an Agricultural Watershed?","volume":"280","author":"Pineux","year":"2017","journal-title":"Geomorphology"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Nesbit, P., Hugenholtz, C., Nesbit, P.R., and Hugenholtz, C.H. (2019). Enhancing UAV\u2013SfM 3D Model Accuracy in High-Relief Landscapes by Incorporating Oblique Images. Remote Sens., 11.","DOI":"10.3390\/rs11030239"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2027","DOI":"10.1007\/s10346-020-01416-4","article-title":"UAVs for Monitoring, Investigation, and Mitigation Design of a Rock Slope with Multiple Failure Mechanisms\u2014A Case Study","volume":"17","author":"Rodriguez","year":"2020","journal-title":"Landslides"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gong, C., Lei, S., Bian, Z., Liu, Y., Zhang, Z., Cheng, W., Gong, C., Lei, S., Bian, Z., and Liu, Y. (2019). Analysis of the Development of an Erosion Gully in an Open-Pit Coal Mine Dump during a Winter Freeze-Thaw Cycle by Using Low-Cost UAVs. Remote Sens., 11.","DOI":"10.3390\/rs11111356"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/B978-0-444-64177-9.00006-0","article-title":"SfM Photogrammetry for GeoArchaeology","volume":"23","author":"Cucchiaro","year":"2020","journal-title":"Dev. Earth Surf. Process."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Kozmus Trajkovski, K., Grigillo, D., and Petrovi\u010d, D. (2020). Optimization of UAV Flight Missions in Steep Terrain. Remote Sens., 12.","DOI":"10.3390\/rs12081293"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Tu, Y.-H., Johansen, K., Aragon, B., Stutsel, B.M., Angel, Y., Camargo, O.A.L., Al-Mashharawi, S.K.M., Jiang, J., Ziliani, M.G., and McCabe, M.F. (2021). Combining Nadir, Oblique, and Fa\u00e7ade Imagery Enhances Reconstruction of Rock Formations Using Unmanned Aerial Vehicles. IEEE Trans. Geosci. Remote Sens., 1\u201313.","DOI":"10.1109\/TGRS.2020.3047435"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.1002\/esp.3609","article-title":"Mitigating Systematic Error in Topographic Models Derived from UAV and Ground-Based Image Networks","volume":"39","author":"James","year":"2014","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Mart\u00ednez-Carricondo, P., Ag\u00fcera-Vega, F., and Carvajal-Ram\u00edrez, F. (2020). Use of UAV-Photogrammetry for Quasi-Vertical Wall Surveying. Remote Sens., 12.","DOI":"10.3390\/rs12142221"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.measurement.2019.02.024","article-title":"UAV Survey of a Coastal Cliff Face\u2013Selection of the Best Imaging Angle","volume":"139","author":"Jaud","year":"2019","journal-title":"Measurement"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2134","DOI":"10.1002\/esp.4871","article-title":"Reducing Systematic Dome Errors in Digital Elevation Models through Better UAV Flight Design","volume":"45","author":"Chandler","year":"2020","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.enggeo.2019.01.013","article-title":"Detection and Analysis of Mass Wasting Events in Chalk Sea Cliffs Using UAV Photogrammetry","volume":"250","author":"Gilham","year":"2019","journal-title":"Eng. Geol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.coastaleng.2018.04.008","article-title":"Cost-Effective Erosion Monitoring of Coastal Cliffs","volume":"138","author":"Westoby","year":"2018","journal-title":"Coast. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.enggeo.2019.04.011","article-title":"A Low-Cost Approach for Determination of Discontinuity Orientation Using Smartphone Images and Application to a Part of Ihlara Valley (Central Turkey)","volume":"254","author":"Ozturk","year":"2019","journal-title":"Eng. Geol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.enggeo.2019.02.028","article-title":"Detection and Geometric Characterization of Rock Mass Discontinuities Using a 3D High-Resolution Digital Outcrop Model Generated from RPAS Imagery\u2013Ormea Rock Slope, Italy","volume":"252","author":"Menegoni","year":"2019","journal-title":"Eng. Geol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1007\/s12665-018-7383-9","article-title":"Open-Pit Mine Geomorphic Changes Analysis Using Multi-Temporal UAV Survey","volume":"77","author":"Xiang","year":"2018","journal-title":"Environ. Earth Sci."},{"key":"ref_26","unstructured":"Fourie, A., and Tibbett, M. (2019, January 3\u20135). Whole-of-Landform Erosion Assessment Using Unmanned Aerial Vehicle Data. Proceedings of the 13th International Conference on Mine Closure, Perth, Australia."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Giacomini, A., Thoeni, K., Santise, M., Diotri, F., Booth, S., Fityus, S., and Roncella, R. (2020). Temporal-Spatial Frequency Rockfall Data from Open-Pit Highwalls Using a Low-Cost Monitoring System. Remote Sens., 12.","DOI":"10.3390\/rs12152459"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"287","DOI":"10.5194\/nhess-18-287-2018","article-title":"Use of a Remotely Piloted Aircraft System for Hazard Assessment in a Rocky Mining Area (Lucca, Italy)","volume":"18","author":"Salvini","year":"2018","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_29","unstructured":"Thoeni, K., Irschara, A., and Giacomini, A. (, January August). Efficient Photogrammetric Reconstruction of Highwalls in Open Pit Coal Mines. Proceedings of the 16th Australasian Remote Sensing and Photogrammetry Conference, Melbourne, Australia."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Ge, L., Li, X., and Ng, A.H.M. (2016, January 10\u201315). UAV for Mining Applications: A Case Study at an Open-Cut Mine and a Longwall Mine in New South Wales, Australia. Proceedings of the International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China.","DOI":"10.1109\/IGARSS.2016.7730412"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"291","DOI":"10.17159\/2411-9717\/2019\/v119n3a8","article-title":"The Use of Unmanned Aircraft System Technology for Highwall Mapping at Isibonelo Colliery, South Africa","volume":"119","author":"Katuruza","year":"2019","journal-title":"J. South Afr. Inst. Min. Metall."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Sayab, M., Aerden, D., Paananen, M., and Saarela, P. (2018). Virtual Structural Analysis of Jokisivu Open Pit Using \u2018Structure-from-Motion\u2019 Unmanned Aerial Vehicles (UAV) Photogrammetry: Implications for Structurally-Controlled Gold Deposits in Southwest Finland. Remote Sens., 10.","DOI":"10.3390\/rs10081296"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"104729","DOI":"10.1016\/j.ijrmms.2021.104729","article-title":"Development and Application of UAV-SfM Photogrammetry for Quantitative Characterization of Rock Mass Discontinuities","volume":"141","author":"Kong","year":"2021","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1431","DOI":"10.1002\/esp.4327","article-title":"Waste Dump Erosional Landform Stability\u2014A Critical Issue for Mountain Mining","volume":"43","author":"Zapico","year":"2018","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"124408","DOI":"10.1016\/j.jclepro.2020.124408","article-title":"Evaluation of Sedimentation Pond Performance for a Cleaner Water Production from an Open Pit Mine at the Edge of the Alto Tajo Natural Park","volume":"280","author":"Zapico","year":"2021","journal-title":"J. Clean. Prod."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1002\/ldr.2605","article-title":"Baseline to Evaluate Off-site Suspended Sediment-related Mining Effects in the Alto Tajo Natural Park, Spain","volume":"28","author":"Zapico","year":"2017","journal-title":"Land Degrad. Dev."},{"key":"ref_37","unstructured":"(2020, January 15). SPH Engineering Ground Station Software|UgCS PC Mission Planning. Available online: https:\/\/www.ugcs.com\/photogrammetry-tool-for-land-surveying."},{"key":"ref_38","unstructured":"(2020, January 15). Agisoft Agisoft Metashape. Available online: https:\/\/www.agisoft.com\/downloads\/installer\/."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.measurement.2016.12.002","article-title":"Assessment of Photogrammetric Mapping Accuracy Based on Variation Ground Control Points Number Using Unmanned Aerial Vehicle","volume":"98","year":"2017","journal-title":"Measurement"},{"key":"ref_40","unstructured":"(2019, July 01). USGS Unmanned Aircraft Systems Data Post-Processing Structure-from-Motion Photogrammetry, Available online: https:\/\/uas.usgs.gov\/nupo\/pdf\/PhotoScanProcessingDSLRMar2017.pdf."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2081","DOI":"10.1002\/esp.4637","article-title":"Guidelines on the Use of Structure-from-motion Photogrammetry in Geomorphic Research","volume":"44","author":"James","year":"2019","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_42","unstructured":"CloudCompare (2020, January 08). Cloud Compare Version 2.6.1. Available online: https:\/\/www.danielgm.net\/cc\/."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.isprsjprs.2013.04.009","article-title":"Accurate 3D Comparison of Complex Topography with Terrestrial Laser Scanner: Application to the Rangitikei Canyon (N-Z)","volume":"82","author":"Lague","year":"2013","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"104214","DOI":"10.1016\/j.jsg.2020.104214","article-title":"3D Digital Outcrop Modelling of the Lower Cretaceous Los Santos Formation Sandstones, Mesa de Los Santos Region (Colombia): Implications for Structural Analysis","volume":"141","author":"Villarreal","year":"2020","journal-title":"J. Struct. Geol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/j.cageo.2014.03.014","article-title":"A New Approach for Semi-Automatic Rock Mass Joints Recognition from 3D Point Clouds","volume":"68","author":"Riquelme","year":"2014","journal-title":"Comput. Geosci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2173","DOI":"10.1007\/s10346-020-01413-7","article-title":"Remote Analysis of an Open-Pit Slope Failure: Las Cruces Case Study, Spain","volume":"17","author":"Ezquerro","year":"2020","journal-title":"Landslides"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"8143","DOI":"10.1080\/01431161.2020.1752950","article-title":"Surveying Coastal Cliffs Using Two UAV Platforms (Multi-Rotor and Fixedwing) and Three Different Approaches for the Estimation of Volumetric Changes","volume":"41","year":"2020","journal-title":"Int. J. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Sanz-Ablanedo, E., Chandler, J., Rodr\u00edguez-P\u00e9rez, J., and Ord\u00f3\u00f1ez, C. (2018). Accuracy of Unmanned Aerial Vehicle (UAV) and SfM Photogrammetry Survey as a Function of the Number and Location of Ground Control Points Used. Remote Sens., 10.","DOI":"10.3390\/rs10101606"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.measurement.2018.02.062","article-title":"Reconstruction of Extreme Topography from UAV Structure from Motion Photogrammetry","volume":"121","year":"2018","journal-title":"Measurement"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Cabo, C., Sanz-Ablanedo, E., Roca-Pardinas, J., and Ordonez, C. (2021). Influence of the Number and Spatial Distribution of Ground Control Points in the Accuracy of UAV-SfM DEMs: An Approach Based on Generalized Additive Models. IEEE Trans. Geosci. Remote Sens., 1\u201310.","DOI":"10.1109\/TGRS.2021.3050693"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2738","DOI":"10.1109\/TGRS.2013.2265295","article-title":"Direct Georeferencing of Ultrahigh-Resolution UAV Imagery","volume":"52","author":"Turner","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Stott, E., Williams, R.D., and Hoey, T.B. (2020). Ground Control Point Distribution for Accurate Kilometre-Scale Topographic Mapping Using an RTK-GNSS Unmanned Aerial Vehicle and SfM Photogrammetry. Drones, 4.","DOI":"10.3390\/drones4030055"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"21","DOI":"10.5623\/cig2016-102","article-title":"Spatial Accuracy of UAV-Derived Orthoimagery and Topography: Comparing Photogrammetric Models Processed with Direct Geo-Referencing and Ground Control Points","volume":"70","author":"Hugenholtz","year":"2016","journal-title":"Geomatica"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"105480","DOI":"10.1016\/j.enggeo.2020.105480","article-title":"Establishing Relationships between Structural Data from Close-Range Terrestrial Digital Photogrammetry and Measurement While Drilling Data","volume":"267","author":"Manzoor","year":"2020","journal-title":"Eng. Geol."},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Menegoni, N., Giordan, D., and Perotti, C. (2020). Reliability and Uncertainties of the Analysis of an Unstable Rock Slope Performed on RPAS Digital Outcrop Models: The Case of the Gallivaggio Landslide (Western Alps, Italy). Remote Sens., 12.","DOI":"10.3390\/rs12101635"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"105205","DOI":"10.1016\/j.enggeo.2019.105205","article-title":"A New Methodological Approach to Assess the Stability of Discontinuous Rocky Cliffs Using In-Situ Surveys Supported by UAV-Based Techniques and 3-D Finite Element Model: A Case Study","volume":"260","author":"Fazio","year":"2019","journal-title":"Eng. Geol."},{"key":"ref_57","unstructured":"(2020, February 22). G\u00e9nie G\u00e9ologique the Talus Royal Method Website. Available online: http:\/\/www.2g.fr\/."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/17\/3353\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:50:55Z","timestamp":1760165455000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/17\/3353"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,24]]},"references-count":57,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["rs13173353"],"URL":"https:\/\/doi.org\/10.3390\/rs13173353","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,8,24]]}}}