{"id":"https://openalex.org/W1969779430","doi":"https://doi.org/10.1016/s0195-6698(81)80043-1","title":"A Problem of Ulam on Planar Graphs","display_name":"A Problem of Ulam on Planar Graphs","publication_year":1981,"publication_date":"1981-12-01","ids":{"openalex":"https://openalex.org/W1969779430","doi":"https://doi.org/10.1016/s0195-6698(81)80043-1","mag":"1969779430"},"language":"en","primary_location":{"id":"doi:10.1016/s0195-6698(81)80043-1","is_oa":true,"landing_page_url":"https://doi.org/10.1016/s0195-6698(81)80043-1","pdf_url":"https://www.sciencedirect.com/science/article/pii/S0195669881800431/pdf","source":{"id":"https://openalex.org/S204851967","display_name":"European Journal of Combinatorics","issn_l":"0195-6698","issn":["0195-6698","1095-9971"],"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":"European Journal of Combinatorics","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":true,"oa_status":"bronze","oa_url":"https://www.sciencedirect.com/science/article/pii/S0195669881800431/pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5032398271","display_name":"J\u00e1nos Pach","orcid":"https://orcid.org/0000-0002-2389-2035"},"institutions":[{"id":"https://openalex.org/I7597260","display_name":"Hungarian Academy of Sciences","ror":"https://ror.org/02ks8qq67","country_code":"HU","type":"government","lineage":["https://openalex.org/I7597260"]}],"countries":["HU"],"is_corresponding":true,"raw_author_name":"J\u00e1nos Pach","raw_affiliation_strings":["Mathematical Institute of the Hungarian Academy of Sciences, R\u00e9altanoda u. 13-15, 1053 Budapest, Hungary","Mathematical Institute of the Hungarian Academy of Sciences, Realtanoda u. 13-15, 1053 Budapest, Hungary"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Mathematical Institute of the Hungarian Academy of Sciences, R\u00e9altanoda u. 13-15, 1053 Budapest, Hungary","institution_ids":["https://openalex.org/I7597260"]},{"raw_affiliation_string":"Mathematical Institute of the Hungarian Academy of Sciences, Realtanoda u. 13-15, 1053 Budapest, Hungary","institution_ids":["https://openalex.org/I7597260"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5032398271"],"corresponding_institution_ids":["https://openalex.org/I7597260"],"apc_list":{"value":3560,"currency":"USD","value_usd":3560},"apc_paid":null,"fwci":0.0,"has_fulltext":true,"cited_by_count":22,"citation_normalized_percentile":{"value":0.08610495,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":97},"biblio":{"volume":"2","issue":"4","first_page":"357","last_page":"361"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11151","display_name":"Advanced Topology and Set Theory","score":0.9887999892234802,"subfield":{"id":"https://openalex.org/subfields/2608","display_name":"Geometry and Topology"},"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/T11151","display_name":"Advanced Topology and Set Theory","score":0.9887999892234802,"subfield":{"id":"https://openalex.org/subfields/2608","display_name":"Geometry and Topology"},"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/T10374","display_name":"Advanced Graph Theory Research","score":0.9832000136375427,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11329","display_name":"Limits and Structures in Graph Theory","score":0.9567000269889832,"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/mathematics","display_name":"Mathematics","score":0.898734450340271},{"id":"https://openalex.org/keywords/countable-set","display_name":"Countable set","score":0.8043196201324463},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.7678773403167725},{"id":"https://openalex.org/keywords/planar-graph","display_name":"Planar graph","score":0.7352250814437866},{"id":"https://openalex.org/keywords/planar","display_name":"Planar","score":0.5476107597351074},{"id":"https://openalex.org/keywords/graph","display_name":"Graph","score":0.48355600237846375},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.47982192039489746}],"concepts":[{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.898734450340271},{"id":"https://openalex.org/C110729354","wikidata":"https://www.wikidata.org/wiki/Q185478","display_name":"Countable set","level":2,"score":0.8043196201324463},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.7678773403167725},{"id":"https://openalex.org/C101837359","wikidata":"https://www.wikidata.org/wiki/Q547823","display_name":"Planar graph","level":3,"score":0.7352250814437866},{"id":"https://openalex.org/C134786449","wikidata":"https://www.wikidata.org/wiki/Q3391255","display_name":"Planar","level":2,"score":0.5476107597351074},{"id":"https://openalex.org/C132525143","wikidata":"https://www.wikidata.org/wiki/Q141488","display_name":"Graph","level":2,"score":0.48355600237846375},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.47982192039489746},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.0},{"id":"https://openalex.org/C121684516","wikidata":"https://www.wikidata.org/wiki/Q7600677","display_name":"Computer graphics (images)","level":1,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1016/s0195-6698(81)80043-1","is_oa":true,"landing_page_url":"https://doi.org/10.1016/s0195-6698(81)80043-1","pdf_url":"https://www.sciencedirect.com/science/article/pii/S0195669881800431/pdf","source":{"id":"https://openalex.org/S204851967","display_name":"European Journal of Combinatorics","issn_l":"0195-6698","issn":["0195-6698","1095-9971"],"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":"European Journal of Combinatorics","raw_type":"journal-article"},{"id":"pmh:oai:infoscience.epfl.ch:129136","is_oa":true,"landing_page_url":"http://infoscience.epfl.ch/record/129136","pdf_url":null,"source":{"id":"https://openalex.org/S4306400487","display_name":"Infoscience (Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I5124864","host_organization_name":"\u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne","host_organization_lineage":["https://openalex.org/I5124864"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"Text"}],"best_oa_location":{"id":"doi:10.1016/s0195-6698(81)80043-1","is_oa":true,"landing_page_url":"https://doi.org/10.1016/s0195-6698(81)80043-1","pdf_url":"https://www.sciencedirect.com/science/article/pii/S0195669881800431/pdf","source":{"id":"https://openalex.org/S204851967","display_name":"European Journal of Combinatorics","issn_l":"0195-6698","issn":["0195-6698","1095-9971"],"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":"European Journal of Combinatorics","raw_type":"journal-article"},"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W1969779430.pdf","grobid_xml":"https://content.openalex.org/works/W1969779430.grobid-xml"},"referenced_works_count":7,"referenced_works":["https://openalex.org/W1530753374","https://openalex.org/W1552744309","https://openalex.org/W1589664198","https://openalex.org/W1605337124","https://openalex.org/W1969233928","https://openalex.org/W2049623622","https://openalex.org/W2577446513"],"related_works":["https://openalex.org/W1701875187","https://openalex.org/W2990956612","https://openalex.org/W3084676277","https://openalex.org/W2541640833","https://openalex.org/W1606013690","https://openalex.org/W4206367340","https://openalex.org/W2086359902","https://openalex.org/W4293743430","https://openalex.org/W3006156235","https://openalex.org/W2073591271"],"abstract_inverted_index":null,"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2024,"cited_by_count":1},{"year":2023,"cited_by_count":3},{"year":2021,"cited_by_count":1},{"year":2013,"cited_by_count":2}],"updated_date":"2026-08-21T09:56:20.448147","created_date":"2025-10-10T00:00:00"}