Mason, Alpheus Thomas,1899-1989, author
Prentice-Hall, 1993
Buku Teks
Graber, Mark A., author
Oxford University Press, 2015
Buku Teks
Nowak, John E., author
Thomson/West, 2010
Buku Teks
Tribe, Laurence H., author
Foundation Press, 1978
Buku Teks
Barron, Jerome A., author
West, 2009
Buku Teks