Solso, Robert L., 1933-, author
Boston, 2002
Buku Teks
Kantowitz, Barry H., author
Cengage Learning, 2015
Buku Teks
Herve Abdi, author
Oxford University Press, 2009
Buku Teks
Robinson, Paul W.
Harper & Row , 1979
Buku Teks
Robinson, Paul W., 1942-
Prentice-Hall, 1981
Buku Teks