https://w3id.org/framester/conceptnet5/cla/la.difficilis.a <https://w3id.org/framester/conceptnet5/schema/RelatedTo> <https://w3id.org/framester/conceptnet5/data/en/difficult> <https://w3id.org/framester/conceptnet5/data/en/obstinate> <https://w3id.org/framester/conceptnet5/data/en/troublesome> <https://w3id.org/framester/conceptnet5/data/en/intractable> risorse dalla linked data cloud