Krech, David, author
McGraw-Hill, 1962
Buku Teks
DeLamater, John D., author
Colorado Westview Press, 2014
Buku Teks
Victoria University of Wellington, 2007
Buku Teks
Taylor, Shelley E., author
Prentice-Hall, 1997
Buku Teks
Baron, Robert A., author
Allyn and Bacon , 1997
Buku Teks