Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field unknown
Is Reference of Weltpostvertrag-de#Sense
Convenzione postale universale-it#Sense
Παγκόσμια ταχυδρομική σύμβαση-el#Sense
Convention postale universelle-fr#Sense
Wereldpostverdrag-nl#Sense
Convenção postal universal-pt#Sense
Universal postal convention-en#Sense
Convenio postal universal-es#Sense
Maailman postiliiton yleissopimus-fi#Sense
Verdenspostkonvention-da#Sense
Världspostkonvention-sv#Sense