Aldo Gangemi Jos Lehmann Valentina Presutti Malvina Nissim Carola Catenacci C-ODO: an OWL Meta-model for Collaborative Ontology Design. 2007 CKC http://ceur-ws.org/Vol-273/paper_38.pdf conf/www/2007ckc db/conf/www/ckc2007.html#GangemiLPNC07