{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T16:51:57Z","timestamp":1773852717255,"version":"3.50.1"},"reference-count":14,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,8,1]],"date-time":"2023-08-01T00:00:00Z","timestamp":1690848000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Agencia Estatal de Investigaci\u00f3n","award":["PID2019-104658GB-I00"],"award-info":[{"award-number":["PID2019-104658GB-I00"]}]},{"name":"Agencia Estatal de Investigaci\u00f3n","award":["MSCA-RISE-2017-777911"],"award-info":[{"award-number":["MSCA-RISE-2017-777911"]}]},{"name":"Agencia Estatal de Investigaci\u00f3n","award":["2021SGR00113"],"award-info":[{"award-number":["2021SGR00113"]}]},{"name":"H2020 European Research Council","award":["PID2019-104658GB-I00"],"award-info":[{"award-number":["PID2019-104658GB-I00"]}]},{"name":"H2020 European Research Council","award":["MSCA-RISE-2017-777911"],"award-info":[{"award-number":["MSCA-RISE-2017-777911"]}]},{"name":"H2020 European Research Council","award":["2021SGR00113"],"award-info":[{"award-number":["2021SGR00113"]}]},{"name":"AGAUR (Generalitat de Catalunya)","award":["PID2019-104658GB-I00"],"award-info":[{"award-number":["PID2019-104658GB-I00"]}]},{"name":"AGAUR (Generalitat de Catalunya)","award":["MSCA-RISE-2017-777911"],"award-info":[{"award-number":["MSCA-RISE-2017-777911"]}]},{"name":"AGAUR (Generalitat de Catalunya)","award":["2021SGR00113"],"award-info":[{"award-number":["2021SGR00113"]}]},{"name":"Acad\u00e8mia de Ci\u00e8ncies i Arts de Barcelona","award":["PID2019-104658GB-I00"],"award-info":[{"award-number":["PID2019-104658GB-I00"]}]},{"name":"Acad\u00e8mia de Ci\u00e8ncies i Arts de Barcelona","award":["MSCA-RISE-2017-777911"],"award-info":[{"award-number":["MSCA-RISE-2017-777911"]}]},{"name":"Acad\u00e8mia de Ci\u00e8ncies i Arts de Barcelona","award":["2021SGR00113"],"award-info":[{"award-number":["2021SGR00113"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Axioms"],"abstract":"<jats:p>The quadratic polynomial differential systems in a plane are the easiest nonlinear differential systems. They have been studied intensively due to their nonlinearity and the large number of applications. These systems can be classified into ten classes. Here, we provide all topologically different phase portraits in the Poincar\u00e9 disc of two of these classes.<\/jats:p>","DOI":"10.3390\/axioms12080756","type":"journal-article","created":{"date-parts":[[2023,8,1]],"date-time":"2023-08-01T09:32:35Z","timestamp":1690882355000},"page":"756","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Phase Portraits of Families VII and VIII of the Quadratic Systems"],"prefix":"10.3390","volume":"12","author":[{"given":"Laurent","family":"Cair\u00f3","sequence":"first","affiliation":[{"name":"Institut Denis Poisson, Universit\u00e9 d\u2019Orleans, Collegium Sciences et Techniques, Batiment de Math\u00e9matiques, Rue de Chartres BP6759, CEDEX 2, 45067 Orl\u00e9ans, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9511-5999","authenticated-orcid":false,"given":"Jaume","family":"Llibre","sequence":"additional","affiliation":[{"name":"Departament de Matem\u00e0tiques, Universitat Aut\u00f2noma de Barcelona, 08193 Bellaterra, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/0022-0396(66)90070-2","article-title":"A Survey of Quadratic Systems","volume":"2","author":"Coppel","year":"1966","journal-title":"J. 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