Leach, John, 1953-
Philadelphia Open University Press 1991,
Buku Teks
Robinson, Paul W.
Harper & Row , 1979
Buku Teks
Solso, Robert L., 1933-, author
Boston, 2002
Buku Teks
Myers, Anne, author
Wadsworth and Cengage Learning, 2012
Buku Teks
Robinson, Paul W., 1942-
Prentice-Hall, 1981
Buku Teks