edited by Jan Fook
Allen & Unwin, 1996
Buku Teks
Babbie, Earl, author
Cal. Wodsworth Pub.Co. , 1986
Buku Teks
edited by George Mckenzie, Jackie Powell, Robin Usher
The Falmer Press, 1997
Buku Teks
Longman Scietific Technical, 1994
Buku Teks
Babbie, Earl
Wadsworth, 1975
Buku Teks