Norton, Henry K.
Allen & Unwin , [date of publication not identified]
Buku Teks
Vandenbosch, Amry
University of Kentucky Press, 1957
Buku Teks
Fishers, David A.
West Publishing Company, 1994
Buku Teks
Asad-ul Iqbal Latif
ISEAS, 2007
Buku Teks
Lu, David
International Studies Group, 1964
Buku Teks