Journal of Combinatorial Theory
{{Infobox journal
| title = Journal of Combinatorial Theory
| cover =
| caption =
| former_name =
| abbreviation = J. Comb. Theory
| mathscinet = J. Combin. Theory
| discipline = Mathematics
| peer-reviewed =
| language = English
| editor =
| publisher = Elsevier
| country =
| history = 1966-present
| frequency = Monthly
| license =
| impact =
| impact-year =
| ISSNlabel = Series A
| ISSN = 0097-3165
| eISSN =
| ISSN2label = Series B
| ISSN2 = 0095-8956
| eISSN2 =
| CODEN =
| JSTOR =
| LCCN =
| OCLC =
| website =
| link1 = https://www.sciencedirect.com/journal/journal-of-combinatorial-theory-series-a
| link1-name = Series A website
| link2 = https://www.sciencedirect.com/journal/journal-of-combinatorial-theory-series-b
| link2-name = Series B website
| boxwidth =
| openaccess = Hybrid
}}
The Journal of Combinatorial Theory, Series A[http://www.elsevier.com/wps/find/journaldescription.cws_home/622862/description Journal of Combinatorial Theory, Series A - Elsevier] and Series B,[http://www.elsevier.com/wps/find/journaldescription.cws_home/622863/description Journal of Combinatorial Theory, Series B - Elsevier] are mathematical journals specializing in combinatorics and related areas. They are published by Elsevier. Series A is concerned primarily with structures, designs, and applications of combinatorics. Series B is concerned primarily with graph and matroid theory. The two series are two of the leading journals in the field and are widely known as JCTA and JCTB.{{citation needed|date=February 2010}}
The journal was founded in 1966 by Frank Harary and Gian-Carlo Rota.They are acknowledged on the journals' title pages and Web sites. See [http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/622862/editorialboard Editorial board of JCTA]; [http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/622863/editorialboard Editorial board of JCTB]. Originally there was only one journal, which was split into two parts in 1971 as the field grew rapidly.
In 2020, most of the editorial board of JCTA resigned to form a new, open access journal Combinatorial Theory. The new journal aims to be a continuation of JCTA independently from Elsevier.{{Cite web|title=Another mass resignation of an editorial board has happened|url=https://twitter.com/wtgowers/status/1305253478047068160|access-date=2020-09-14|website=Twitter|language=en}}{{Cite web|title=Combinatorial Theory: a new mathematician-owned and fully open access journal|url=http://fpsac.org/2020/09/13/CombinatorialTheoryJournal/}}{{Cite web|title=Website of the new journal|url=https://combinatorial-theory.org}} It published its first issue in December 2021.{{Cite journal|last=Editorial Team|first=Combinatorial Theory|date=2021-12-09|title=Editorial|url=https://escholarship.org/uc/item/4vb046p0|journal=Combinatorial Theory|volume=1|doi=10.5070/C61055307|s2cid=245076810|issn=2766-1334|doi-access=free}}
Influential articles
Influential articles that appeared in the journal include Katona's elegant proof{{cite journal
| first = G.O.H.
| last = Katona
| author-link = Gyula O. H. Katona
| title = A simple proof of the Erdös-Chao Ko-Rado theorem
| journal = Journal of Combinatorial Theory, Series B
| volume = 13
| year = 1972
| issue = 2
| pages = 183–184
| doi = 10.1016/0095-8956(72)90054-8
| doi-access = free}} of the Erdős–Ko–Rado theorem and a series of papers spanning over 500 pages, appearing from 1983{{cite journal
| first=Neil
| last=Robertson
|author2=P.D. Seymour
| title=Graph Minors. I. Excluding a forest
| journal=Journal of Combinatorial Theory, Series B
| volume=35
| issue=1
| year=1983
| pages=39–61
| doi=10.1016/0095-8956(83)90079-5
| doi-access = free}} to 2004,{{cite journal
| first=Neil
| last=Robertson
|author2=P.D. Seymour
| title=Graph Minors. XX. Wagner's conjecture
| journal=Journal of Combinatorial Theory, Series B
| volume=92
| issue=2
| year=2004
| pages=325–357
| doi=10.1016/j.jctb.2004.08.001
| doi-access = free}} by Neil Robertson and Paul D. Seymour on the topic of graph minors, which together constitute the proof of the graph minors theorem. Two articles proving Kneser's conjecture,{{cite journal
| first=László
| last=Lovász
| title=Kneser's conjecture, chromatic number, and homotopy
| journal=Journal of Combinatorial Theory, Series A
| volume=25
| issue=3
| year=1978
| pages=319–324
| doi=10.1016/0097-3165(78)90022-5
| doi-access = }}{{cite journal
| first=Imre
| last=Bárány
| title=A short proof of Kneser's conjecture
| journal=Journal of Combinatorial Theory, Series A
| volume=25
| issue=3
| year=1978
| pages=325–326
| doi=10.1016/0097-3165(78)90023-7
| doi-access = }} the first by László Lovász and the other by Imre Bárány, appeared back-to-back in the same issue of the journal.