Longres, John F.
F.E. Peacock Publisher, Inc, 1990
Buku Teks
Flacks, Richard
Columbia University Press, 1988
Buku Teks
Bardes, Barbara A., author
Thomson/Wadsworth, 2006
Buku Teks
Nevaer, Louis E.V.
Quorum Books , 1987
Buku Teks
Monks, Robert A. G., 1933-, author
Blackwell, 2001
Buku Teks