Sherif, Muzafer, author
John Wiley & Sons, 1947
Buku Teks
Todosijevic, Bojan, author
VDM Verlag Dr. Muller, 2008
Buku Teks
Gerungan, W. A., author
Eresco, 1972
Buku Teks
DeLamater, John D., author
Colorado Westview Press, 2014
Buku Teks
Pines, Ayala, author
McGraw-Hill, 1993
Buku Teks