Petra Becker-Pechau Pierre Grenon Mark Lycett Christopher Partridge Jörg Pechau Dirk Siebert Philosophy, Ontology, and Information Systems. 62-66 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3344&spage=62 2004 conf/ecoopw/2004 ECOOP Workshops db/conf/ecoopw/ecoopw2004.html#Becker-PechauGLPPS04