Shaughnessy, John J., author
McGrawhill , 1994
Buku Teks
bt Peter Banister ... [and others]
Open University Press, 2006
Buku Teks
Howitt, Dennis, author
Routledge , 2000
Buku Teks
Howitt, Dennis, author
Routledge, 2000
Buku Teks
BPS Blackwell, 2004
Buku Teks