{"id":"https://openalex.org/W2026672981","doi":"https://doi.org/10.1016/0097-3165(81)90025-x","title":"On Sperner families in which no k sets have an empty intersection, II","display_name":"On Sperner families in which no k sets have an empty intersection, II","publication_year":1981,"publication_date":"1981-05-01","ids":{"openalex":"https://openalex.org/W2026672981","doi":"https://doi.org/10.1016/0097-3165(81)90025-x","mag":"2026672981"},"language":"en","primary_location":{"id":"doi:10.1016/0097-3165(81)90025-x","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0097-3165(81)90025-x","pdf_url":null,"source":{"id":"https://openalex.org/S128556326","display_name":"Journal of Combinatorial Theory Series A","issn_l":"0097-3165","issn":["0097-3165","1096-0899"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Combinatorial Theory, Series A","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5113592049","display_name":"Hans-Dietrich O. F. Gronau","orcid":null},"institutions":[{"id":"https://openalex.org/I4665924","display_name":"University of Rostock","ror":"https://ror.org/03zdwsf69","country_code":"DE","type":"education","lineage":["https://openalex.org/I4665924"]}],"countries":["DE"],"is_corresponding":true,"raw_author_name":"Hans-Dietrich O.F Gronau","raw_affiliation_strings":["Sektion Mathematik, Wilhelm-Pieck-Universit\u00e4t, 25 Rostock, German Democratic Republic"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Sektion Mathematik, Wilhelm-Pieck-Universit\u00e4t, 25 Rostock, German Democratic Republic","institution_ids":["https://openalex.org/I4665924"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5113592049"],"corresponding_institution_ids":["https://openalex.org/I4665924"],"apc_list":{"value":4210,"currency":"USD","value_usd":4210},"apc_paid":null,"fwci":2.6398,"has_fulltext":false,"cited_by_count":14,"citation_normalized_percentile":{"value":0.9127907,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":89,"max":94},"biblio":{"volume":"30","issue":"3","first_page":"298","last_page":"316"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11329","display_name":"Limits and Structures in Graph Theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/2607","display_name":"Discrete Mathematics and Combinatorics"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11329","display_name":"Limits and Structures in Graph Theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/2607","display_name":"Discrete Mathematics and Combinatorics"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11797","display_name":"graph theory and CDMA systems","score":0.9979000091552734,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10849","display_name":"Finite Group Theory Research","score":0.9955000281333923,"subfield":{"id":"https://openalex.org/subfields/2607","display_name":"Discrete Mathematics and Combinatorics"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/intersection","display_name":"Intersection (aeronautics)","score":0.8658105134963989},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.5731978416442871},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.3934018611907959},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.3890373110771179},{"id":"https://openalex.org/keywords/geography","display_name":"Geography","score":0.19154629111289978},{"id":"https://openalex.org/keywords/cartography","display_name":"Cartography","score":0.07280442118644714}],"concepts":[{"id":"https://openalex.org/C64543145","wikidata":"https://www.wikidata.org/wiki/Q162942","display_name":"Intersection (aeronautics)","level":2,"score":0.8658105134963989},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.5731978416442871},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.3934018611907959},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.3890373110771179},{"id":"https://openalex.org/C205649164","wikidata":"https://www.wikidata.org/wiki/Q1071","display_name":"Geography","level":0,"score":0.19154629111289978},{"id":"https://openalex.org/C58640448","wikidata":"https://www.wikidata.org/wiki/Q42515","display_name":"Cartography","level":1,"score":0.07280442118644714}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/0097-3165(81)90025-x","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0097-3165(81)90025-x","pdf_url":null,"source":{"id":"https://openalex.org/S128556326","display_name":"Journal of Combinatorial Theory Series A","issn_l":"0097-3165","issn":["0097-3165","1096-0899"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Combinatorial Theory, Series A","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":13,"referenced_works":["https://openalex.org/W1972392483","https://openalex.org/W2017307105","https://openalex.org/W2025324955","https://openalex.org/W2043091249","https://openalex.org/W2055981802","https://openalex.org/W2070725465","https://openalex.org/W2073286344","https://openalex.org/W2087567316","https://openalex.org/W2395469966","https://openalex.org/W4213252296","https://openalex.org/W4300514222","https://openalex.org/W6632048837","https://openalex.org/W6712202753"],"related_works":["https://openalex.org/W2899084033","https://openalex.org/W2748952813","https://openalex.org/W1979597421","https://openalex.org/W2007980826","https://openalex.org/W4245490552","https://openalex.org/W4225152035","https://openalex.org/W2061531152","https://openalex.org/W3002753104","https://openalex.org/W2077600819","https://openalex.org/W1587224694"],"abstract_inverted_index":null,"counts_by_year":[{"year":2021,"cited_by_count":1},{"year":2020,"cited_by_count":1}],"updated_date":"2026-08-21T09:56:20.448147","created_date":"2025-10-10T00:00:00"}
