Oceana Publications, 1958
Buku Teks
Nowak, John E.
Thomson/West, 2010
Buku Teks
Barron, Jerome A.
West, 2009
Buku Teks
Smith, Glenn C.
John Wiley & Sons, 2012
Buku Teks
John Ferejohn, Jack N. Rakove, Jonathan Riley
Cambridge University Press, 2001
Buku Teks