Serow, A. G., & Ladd, E. C. (1990). The American polity reader. New York: Norton.
Dyfyniad Arddull ChicagoSerow, Ann Gostyn, và Everett Carll Ladd. The American Polity Reader. New York: Norton, 1990.
Dyfyniad MLASerow, Ann Gostyn, và Everett Carll Ladd. The American Polity Reader. New York: Norton, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.