Crotty, William J., author
Little, Brown, 1980
Buku Teks
Horwitz, Morton J., author
Harvard University Press, 1977
Buku Teks
Tribe, Laurence H., author
Foundation Press, 1988
Buku Teks
Current, Richard N., author
Alfred A. Knopf, 1965
Buku Teks
edited by Henry Steele Commager
Appleton-Century-Crofts, 1949
Buku Referensi