Zastrow, Charles, author
Thomson Brooks/Cole, 2006
Buku Teks
Cournoyer, Barry R., author
Brooks/Cole Cengage Learning, 2011
Buku Teks
Dubois, Brenda, 1949-, author
Allyn and Boston, 1992
Buku Teks
Gore, M.S., author
Asia Publishing House, 1965
Buku Teks
Cohen, Nathan Edward, author
National Ass. of Workker, 1964
Buku Teks