Maurice Margenstern Guentcho Skordev Tools for devising cellular automata in the hyperbolic 3D space. 369-398 2003 58 Fundam. Inform. 2003 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=58&issue=3&spage=369 db/journals/fuin/fuin58.html#MargensternS03