Wolfgang De Meuter Theo D'Hondt Jessie Dedecker Intersecting Classes and Prototypes. 37-45 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2890&spage=37 2003 conf/ershov/2003 Ershov Memorial Conference db/conf/ershov/ershov2003.html#MeuterDD03