J. Stuart Aitken Bonnie L. Webber Jonathan Bard Part-of Relations in Anatomy Ontologies: A Proposal for RDFS and OWL Formalisations. 166-177 2004 conf/psb/2004 Pacific Symposium on Biocomputing http://helix-web.stanford.edu/psb04/aitken.pdf db/conf/psb/psb2004.html#AitkenWB04