edited by Christina Hughes
Open University Press, 2003
Buku Teks SO
Borg, Walter R.
David Mc Kay Co., 1963
Buku Teks
Allyn and Bacon , 1971
Buku Teks
Woolfolk, Anita E.
Allyn and Bacon , 1995
Buku Teks
edited by David Nice
Councils and Education Press, 1986
Buku Teks SO