C 116.857(Karton) 

congress fifteenth world-postal-union.-15. 
congress of the world postal union. 15.con 
gres de l'union postale universelle. 157 
Congreso postal universal. 15.Weltpgstkongress.-(
Wien: Frick 1964). 20 S. 4 
[Umschlagt.] 
(United Nations Vforld.)
(Kongress-Sonderpublikation. 5.)