Cowan, Douglas E., author
BlackWell Publishing, 2007
Buku Teks
Melton, J. Gordon, author
Garland Publishing, 1986
Buku Referensi
Muhammad Qodari, author
Fakultas Psikologi Universitas Indonesia, 1997
UI - Skripsi (Membership)
Lewis, I.M.
Cambridge University Press , 1996
Buku Teks
Jarvie, Ian C., author
Routledge and Kegan Paul, 1967
Buku Teks