Barker, Roger A.
Psychology Press, 1999
Buku Teks
Middleton, Robert Gordon, 1908-
Bombay: D.B. Taraporevala Sons & Private, 1972
Buku Teks
Michael G. Grantham, editor
Routledge, 2011
Buku Teks
Porter, Lindsay
Haynes Publishing, 1991
Buku Referensi
Adi Setiadi
2001
UI - Skripsi Membership