Cowen, Zelman, author
North-Western University Press, 1965
Buku Teks
Stewart, Robert B., author
Macmillan, 1939
Buku Teks
Underhill, Frank H., author
Duke University Press, 1956
Buku Teks
Keith, Arthur Berriedale, 1879-1944, author
British Council, 1940
Buku Teks
Mansergh, Nicholas, author
Royal Institute Of International Affair, 1948
Buku Teks