Marion Gremse Antje Chang Ida Schomburg Andreas Grote Maurice Scheer Christian Ebeling Dietmar Schomburg The BRENDA Tissue Ontology (BTO): the first all-integrating ontology of all organisms for enzyme sources. 507-513 2011 39 Nucleic Acids Research Database-Issue http://dx.doi.org/10.1093/nar/gkq968 db/journals/nar/nar39.html#GremseCSGSES11