1
Έκδοση 1962
“...United Nations. Office of Public Information....”
Βιβλίο
2
Έκδοση 1975
“...United Nations. Office of Public Information....”Full text available from Military Database: 03/01/1988 to 1996
Full text available from Research Library: 03/01/1988 to 1996
Full text available from Social Science Database: 03/01/1988 to 1996
Ηλεκτρονική πηγή
Επιστημονικό περιοδικό
