{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2022,4,5]],"date-time":"2022-04-05T21:03:04Z","timestamp":1649192584268},"reference-count":11,"publisher":"Elsevier BV","issue":"1-3","license":[{"start":{"date-parts":[[1989,1,1]],"date-time":"1989-01-01T00:00:00Z","timestamp":599616000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"},{"start":{"date-parts":[[2013,7,17]],"date-time":"2013-07-17T00:00:00Z","timestamp":1374019200000},"content-version":"vor","delay-in-days":8963,"URL":"https:\/\/www.elsevier.com\/open-access\/userlicense\/1.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Discrete Applied Mathematics"],"published-print":{"date-parts":[[1989]]},"DOI":"10.1016\/0166-218x(92)90289-m","type":"journal-article","created":{"date-parts":[[2002,12,10]],"date-time":"2002-12-10T21:10:39Z","timestamp":1039554639000},"page":"247-260","source":"Crossref","is-referenced-by-count":0,"title":["An algebraic point of view of the data structures of database systems"],"prefix":"10.1016","volume":"24","author":[{"given":"Dan A.","family":"Simovici","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Corina","family":"Reischer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"78","reference":[{"key":"10.1016\/0166-218X(92)90289-M_BIB1","unstructured":"B. Beeri and P.A. Bernstein, Computational problems related to the design of normal form relational schemas, unpublished manuscript (see also [3])."},{"issue":"1","key":"10.1016\/0166-218X(92)90289-M_BIB2","first-page":"1","article-title":"Semantics in complete lattices for relational database functional dependencies","volume":"XXVIII","author":"Breazu","year":"1982","journal-title":"An. St. Univ. \u201cAl. I. Cuza\u201d"},{"key":"10.1016\/0166-218X(92)90289-M_BIB3","series-title":"A Guide to the Theory of NP-Completeness","article-title":"Computers and Intractability","author":"Garey","year":"1979"},{"key":"10.1016\/0166-218X(92)90289-M_BIB4","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/0020-0255(87)90004-1","article-title":"Towards an abstract theory of integrity constraints in relational databases","volume":"41","author":"Jurgensen","year":"1987","journal-title":"Inform. Sci."},{"key":"10.1016\/0166-218X(92)90289-M_BIB5","series-title":"Complexity of Computer Computations","article-title":"Reducibility among combinatorial problems","author":"Karp","year":"1972"},{"issue":"10","key":"10.1016\/0166-218X(92)90289-M_BIB6","doi-asserted-by":"crossref","first-page":"3159","DOI":"10.1002\/j.1538-7305.1983.tb03470.x","article-title":"An algebraic theory of relational databases","volume":"62","author":"Lee","year":"1983","journal-title":"Bell System Tech. J."},{"key":"10.1016\/0166-218X(92)90289-M_BIB7","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1137\/0211025","article-title":"Planar formulae and their uses","volume":"11","author":"Lichtenstein","year":"1982","journal-title":"SIAM J. Comput."},{"key":"10.1016\/0166-218X(92)90289-M_BIB8","series-title":"Proceedings 4th South-eastern Conference on Combinatorics, Graph Theory, and Computing","first-page":"3","article-title":"Coverings and colorings of hypergraphs","author":"Lov\u00e1sz","year":"1973"},{"issue":"2","key":"10.1016\/0166-218X(92)90289-M_BIB9","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1016\/0022-0000(78)90009-0","article-title":"Candidate keys for relations","volume":"17","author":"Luchessi","year":"1978","journal-title":"J. Comput. System Sci."},{"key":"10.1016\/0166-218X(92)90289-M_BIB10","series-title":"The Theory of Relational Databases","author":"Maier","year":"1983"},{"key":"10.1016\/0166-218X(92)90289-M_BIB11","first-page":"309","article-title":"Graph theory as a source for difficult problems for relational databases","volume":"50","author":"Simovici","year":"1978","journal-title":"Congr. Numer."}],"container-title":["Discrete Applied Mathematics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0166218X9290289M?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0166218X9290289M?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2019,4,13]],"date-time":"2019-04-13T05:55:42Z","timestamp":1555134942000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/0166218X9290289M"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989]]},"references-count":11,"journal-issue":{"issue":"1-3","published-print":{"date-parts":[[1989]]}},"alternative-id":["0166218X9290289M"],"URL":"https:\/\/doi.org\/10.1016\/0166-218x(92)90289-m","relation":{},"ISSN":["0166-218X"],"issn-type":[{"value":"0166-218X","type":"print"}],"subject":[],"published":{"date-parts":[[1989]]}}}