Richard Cole Peter Becker 0002 Navigation Spaces for the Conceptual Analysis of Software Structure. 113-128 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3403&spage=113 2005 conf/icfca/2005 ICFCA db/conf/icfca/icfca2005.html#ColeB05