Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field unknown
Is Reference of Umhüllende-de#Sense
Enveloppante-fr#Sense
Hüllkurve-de#Sense
Envelope-en#Sense
Omhullende-nl#Sense
Omhullingskromme-nl#Sense