edited by Stefan Puglisi-Allegra and Alberto Oliverio
Kluwer, 1990
Buku Teks
edited by Harry N. Shair, Gordon A. Barr, Myron A. Hofer
Oxford University Press , 1991
Buku Teks
Hofer, Myron A
W.H. Freeman and Company , 1981
Buku Teks
Fakultas Psikologi Universitas Indonesia, 2004
UI - Skripsi (Membership)
Lovelace, Richard Perry, author
John Wiley & Sons, 1990
Buku Teks