National Drug Data File Ontology for Geography Markup Language (GML3.0) Source
http://loki.cae.drexel.edu/~wbs/ontology/2004/09/ogc-gml#_Ring http://purl.bioontology.org/ontology/NDDF/003316 LOOM
http://loki.cae.drexel.edu/~wbs/ontology/2004/09/ogc-gml#Ring http://purl.bioontology.org/ontology/NDDF/003316 LOOM