National Drug Data File	Chemical Methods Ontology	Source
http://purl.bioontology.org/ontology/NDDF/008844	http://purl.obolibrary.org/obo/CHEBI_33418	LOOM
http://purl.bioontology.org/ontology/NDDF/002883	http://purl.obolibrary.org/obo/CHEBI_28262	LOOM
http://purl.bioontology.org/ontology/NDDF/001343	http://purl.obolibrary.org/obo/CHEBI_35255	LOOM
http://purl.bioontology.org/ontology/NDDF/001396	http://purl.obolibrary.org/obo/CHEBI_35255	LOOM