First published in May 195s by the United Nations
Educational, Scient$% and Culfural Organization
13 avenue Kliber, Paris-16e
2nd impresrion January 1956
Printed by Gassmann S. A., Soleure (Switzerland)
0 Unesco 1956
Prinied in Suttrsrland
CUA. 55 D. 15 Aa