Schmidt, S. W., Bardes, B. A., & Shelley, M. C. (1999). American government and politics today / Steffen W. Schmidt, Mack C. Shelley, Barbara A. Bardes (1999-2000 edition.). West/Wadworth.

Schmidt, Steffen W., Barbara A. Bardes, and Mack C. Shelley. American Government and Politics Today / Steffen W. Schmidt, Mack C. Shelley, Barbara A. Bardes. 1999-2000 edition. Belmont, Calif. ; London: West/Wadworth, 1999.

Schmidt, Steffen W., et al. American Government and Politics Today / Steffen W. Schmidt, Mack C. Shelley, Barbara A. Bardes. 1999-2000 edition. West/Wadworth, 1999.