https://w3id.org/framester/conceptnet5/data/en/carboxylic.a <https://w3id.org/framester/conceptnet5/schema/RelatedTo> <https://w3id.org/framester/conceptnet5/data/en/carboxyl> <https://w3id.org/framester/conceptnet5/data/en/functional_group> risorse dalla linked data cloud