Frank Dylla Reinhard Moratz Exploiting Qualitative Spatial Neighborhoods in the Situation Calculus. 304-322 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3343&spage=304 2004 conf/spatialCognition/2004 Spatial Cognition db/conf/spatialCognition/spatialCognition2004.html#DyllaM04