Palmer, Vance
Melbourne University Press, 1940
Buku Teks SO
Gor`kiy, Aleksey Maksimovich
Foreign Languages Publishing, [Date of publication not identified]
Buku Teks SO
edited by Gregory A. Kimble, Michael Wertheimer, Charlotte White
American Psychological Association, 1991
Buku Teks SO
Stewart, Ian Charles
Pranawajati, 1990
Buku Referensi
by Andrew C. Garrord, Lisa Smulyan, Sally I. Powers and Robert Kilkenny
Allyn and Bacon, 2002
Buku Teks SO