Farley, John E., author
Prentice-Hall, 1992
Buku Teks
Fulcher, James, author
Oxford University Press, 2007
Buku Teks
Lapiere, Richard T., author
McGraw-Hill, 1946
Buku Teks
edited by Adrian Tomer, Grafton T. Eliason, Paul T.P. Wong
Lawrence Erlbaum Associates, 2007
Buku Teks
Roberts, Don D.
Mouton, 1973
Buku Teks