Francesco Calimeri Wolfgang Faber Gerald Pfeifer Nicola Leone Pruning Operators for Disjunctive Logic Programming Systems. 183-214 2006 71 Fundam. Inform. 2-3 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=71&issue=2&spage=183 db/journals/fuin/fuin71.html#CalimeriFPL06