edited by Robert W. Tucker, Charles B. Keely and Linda Wrigley
Westview Press, 1992
Buku Teks SO
edited by Congressional Quarterly
Congresseional Quarterly, 1986
Buku Teks SO
Buku Teks
Hunter, Robert E.
Praeger, 1982
Buku Teks
Lippmann, Walter
Little, Brown, 1943.
Buku Teks SO