King, Gareth, author
Routledge, 2005
Buku Teks
Othman, Zaharah, author
Routledge, 1995
Buku Teks
Cowles, Roy T., author
South China Peniel Press, 1949
Buku Referensi
Fried, George H., author
McGraw-Hill, 1995
Buku Teks
Vuoang, Tuan Duc
Routledge , 1994
Buku Teks