{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T22:36:13Z","timestamp":1784241373913,"version":"3.55.0"},"reference-count":3,"publisher":"Elsevier BV","issue":"3","license":[{"start":{"date-parts":[[1990,2,1]],"date-time":"1990-02-01T00:00:00Z","timestamp":633830400000},"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":8567,"URL":"https:\/\/www.elsevier.com\/open-access\/userlicense\/1.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Theoretical Computer Science"],"published-print":{"date-parts":[[1990,2]]},"DOI":"10.1016\/0304-3975(90)90129-6","type":"journal-article","created":{"date-parts":[[2002,7,26]],"date-time":"2002-07-26T03:48:55Z","timestamp":1027655335000},"page":"277-303","source":"Crossref","is-referenced-by-count":71,"title":["Theory of 2-structures, part I: Clans, basic subclasses, and morphisms"],"prefix":"10.1016","volume":"70","author":[{"given":"A.","family":"Ehrenfeucht","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G.","family":"Rozenberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","reference":[{"key":"10.1016\/0304-3975(90)90129-6_BIB1","series-title":"Universal Algebra","author":"Cohn","year":"1965"},{"key":"10.1016\/0304-3975(90)90129-6_BIB2","series-title":"Graph Theory","author":"Harary","year":"1969"},{"key":"10.1016\/0304-3975(90)90129-6_BIB3","series-title":"Category Theory","author":"Herrlich","year":"1973"}],"container-title":["Theoretical Computer Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0304397590901296?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0304397590901296?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2019,4,13]],"date-time":"2019-04-13T03:57:04Z","timestamp":1555127824000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/0304397590901296"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,2]]},"references-count":3,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1990,2]]}},"alternative-id":["0304397590901296"],"URL":"https:\/\/doi.org\/10.1016\/0304-3975(90)90129-6","relation":{},"ISSN":["0304-3975"],"issn-type":[{"value":"0304-3975","type":"print"}],"subject":[],"published":{"date-parts":[[1990,2]]}}}