Wilson, James Q., author
D.C. Heath, 1995
Buku Teks
Wilson, James Q., author
D.C. Helath and Co., 1986
Buku Teks
by William J. Keefe ... [and others]
The Dorsey Press, 1983
Buku Teks
Dolbeare, Kenneth M., author
D.C. Heath, 1985
Buku Teks
Dunn, James A.
MIT Press, 1981
Buku Teks