Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field unknown
Is Reference of Convention postale universelle-fr#Sense
Universal Postal Convention-en#Sense
Wereldpostverdrag-nl#Sense
Convenção Postal Universal-pt#Sense
Convenio Postal Universal-es#Sense
Verdenspostkonventionen-da#Sense
Weltpostvertrag-de#Sense
Wereldpostconventie-nl#Sense
Convenzione postale universale-it#Sense