Milne, R.S.
Federal Publications, 1977
Buku Teks
Archipelago Press, 2006
Buku Referensi
Oxford University Press, 1987
Buku Teks
Deutsch, Karl W
Houghton Mifflin, 1970
Buku Teks
Abdul Razak Baginda, author
Asean Academic Press, 2003
Buku Teks
Schmidt, Steffen W., author
Wadsworth, 2009
Buku Teks