Walter Didimo Giuseppe Liotta Maurizio Patrignani HV-planarity: Algorithms and complexity. 72-90 2019 99 J. Comput. Syst. Sci. https://doi.org/10.1016/j.jcss.2018.08.003 https://www.wikidata.org/entity/Q62042358 db/journals/jcss/jcss99.html#DidimoLP19