Royal Institute of International Affairs , 1939
Buku Teks
Jansen, Marius B., author
Rand Mc.Nally College Publishing , 1975
Buku Teks
Willoughby, Westel W., author
John Hopkins Press, 1927
Buku Teks
Youli, Sun
St. Martin's Press, 1993
Buku Teks
Kanshik, Devendra, author
Sterling Publisher, 1975
Buku Teks