Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field Subject Field/5211003
Is Reference of Seaman's book-en#Sense
Cédula marítima-pt#Sense
Ναυτικό φυλλάδιο-el#Sense
Zeemansboekje-nl#Sense
Brevet de marin-fr#Sense