Marbun, Johannes, author
Fakultas Psikologi Universitas Indonesia, 1997
UI - Tesis Membership
Fifi F. Embut, author
Fakultas Psikologi Universitas Indonesia, 1989
UI - Skripsi Membership
Munawir Yusuf, author
Fakultas Psikologi Universitas Indonesia, 1996
UI - Tesis Membership
Viaud, Gaston, author
Hutchirson, 1968
Buku Teks
Gardner, Howard, author
Basic Books, 1983
Buku Teks