Seng, Kenneth Wee Kim
University of Singapore, 1976
Buku Teks
Pace, P.J.
Pitman, 1992
Buku Teks
Coertze, R.D.
ABRA , 1987
Buku Teks
Menski, Werner F.
Curzon Press, 2001
Buku Teks
university of Malaya Press, [date of publication not identified]
Buku Teks