Pirages, Dennis C.
Duxbury Press, 1978
Buku Teks
Deutsch, Karl W
Prentice-Hall, 1978
Buku Teks
Spero, Joan Edelman, author
Routledge, 1994
Buku Teks
Wright, Quincy, author
Appleton-Century-Crofts, 1955
Buku Teks
Forsythe, David P., 1941-, author
Cambridge University Press, 2012
Buku Teks