Sargent, S. W. Stansfeld, author
The Ronald Press, 1966
Buku Teks
Sherif, Muzafer, author
Harper Row, 1969
Buku Teks
editor Kurt W. Back
John Wiley, 1972
Buku Teks
Feldman, Robert S., author
McGraw-Hill, 1985
Buku Teks
Michael a. Hogg; Graham M. Vaughan
Prentice-Hall, 2002
Buku Teks