Andrzej Ehrenfeucht Jurriaan Hage Tero Harju Grzegorz Rozenberg The Embedding Problem for Switching Classes of Graphs. 115-134 2006 74 Fundam. Inform. 1 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=74&issue=1&spage=115 db/journals/fuin/fuin74.html#EhrenfeuchtHHR06