Tatsuya Kushida Toshihisa Takagi Ken-ichiro Fukuda Event Ontology: A Pathway-Centric Ontology for Biological Processes. 152-163 2006 conf/psb/2006 Pacific Symposium on Biocomputing http://psb.stanford.edu/psb-online/proceedings/psb06/kushida.pdf db/conf/psb/psb2006.html#KushidaTF06