Sousa, John J., author
Rhode Island Consortium, 1990
Buku Teks
Bettelheim, Frederick A., author
Thomson, Brooks/Cole, 2007
Buku Teks
Bodner, George M.
Burgess, 1981
Buku Teks
Landesberg, Joseph M., 1903-1994, author
Brooks/Cole Cengage Learning, 2012
Buku Teks
Frantz, Harper W., author
W.H. Freeman, 1968
Buku Teks