Nguyen, van Canh
Stanford: Hoover Institution Press, Stanford University, 1983
Buku Teks
Emil Reza Razali, examiner
New York Barron's Educational Series 1970,
Buku Teks
Hongkong Kingsway International Publications 1981
Buku Referensi
Chang Liu
New York : Routledge , 2007
Buku Teks
Waldron, Arthur
New York Cambridge University Press 1992,
Buku Teks