Derbyshire, Ian
Chambers, 1990
Buku Teks
Woll, Peter, author
Little, Brown, 1982
Buku Teks
Irish, Marian D., author
Prentice-Hall, 1962
Buku Teks
edited by Pietro S. Nivola, David H. Rosenbloom ; with forewords by Nelson W. Polsby and Theodore J. Lowi
St. Martin's Press, 1990.
Buku Teks
Starling, Grover, author
The Dorsey Press, 1982
Buku Teks