* {{Citation|last=Havel|first=Václav|author-link=V. J. Havel|year=1955|title=A remark on the existence of finite graphs|language=cs|journal=Časopis pro pěstování matematiky|volume=80|pages=477–480|url=http://eudml.org/doc/19050|accessdate=2019-04-23|archive-date=2017-07-29|archive-url=https://web.archive.org/web/20170729174826/https://eudml.org/doc/19050|dead-url=no}} | * {{Citation|last=Havel|first=Václav|author-link=V. J. Havel|year=1955|title=A remark on the existence of finite graphs|language=cs|journal=Časopis pro pěstování matematiky|volume=80|pages=477–480|url=http://eudml.org/doc/19050|accessdate=2019-04-23|archive-date=2017-07-29|archive-url=https://web.archive.org/web/20170729174826/https://eudml.org/doc/19050|dead-url=no}} |