D.C Heath and Company, 1973
Buku Teks
Hergenhahn, B.R., 1934-, author
Wadsworth, 2009
Buku Teks
Nietzel, Michael T., author
Prentice-Hall, 1987
Buku Teks
Argyle, Michael, author
Routledge & Kegan Paul, 2000
Buku Teks
Nietzel, Michael T., author
Prentice-Hall, 1998
Buku Teks