Babbie, Earl, author
Thomson/Wadsworth, 2004
Buku Teks
Babbie, Earl, author
Wadsworth, 1991
Buku Teks
May, Tim, author
Open University Press, 2001
Buku Teks
Crotty, Michael, author
Allend & Unwin, 1998
Buku Teks
Babbie, Earl, author
Wadsworth, 1998
Buku Teks