Kolb, David A., author
Prentice-Hall, 1974
Buku Teks
Highsmith, Richard M., Jr.
J.B.Lippincott Co., 1963
Buku Teks
Curley, Anthony J.
Harper & Row , 1979
Buku Teks
Guy, Dan M., author
Harcourt Brace Jovanovich, 1990
Buku Teks
Boella, M. J.
Barrie and Jenkins , 1974
Buku Teks