Graber, Doris A.
Congressional Quarterly Press, 1980
Buku Teks SO
Williams, Patrick, 1930-
Greenwood Press, 1978
Buku Teks SO
Alison Alexander, Jarice Hanson, editor
McGraw-Hill/Dushkin, 2001
Buku Teks SO
Agee, Warren Kendall
Harper & Row Publishers, 1986
Buku Teks SO
Ann N. Crigler, editor
The University of Michigan Press, 2001
Buku Teks SO