* Information System on Graph Classes and their Inclusions (ISGCI) * https://www.graphclasses.org * https://doc.sagemath.org/html/en/reference/graphs/sage/graphs/isgci.html * https://www.graphclasses.org/data.zip * Hierarchy of parameters (HOPS) * https://vaclavblazej.github.io/parameters/ * FindStat * https://www.findstat.org/StatisticsDatabase/?Domain=Graphs * Wikidata * https://www.wikidata.org/w/index.php?title=Special:WhatLinksHere/Q722659&limit=500