Campbell, J. E. a. G. (2000). Before the vote: Forecasting American national elections. SAGE Publications, Inc..
Cita Chicago (17th ed.)Campbell, James E. and Garand. Before the Vote: Forecasting American National Elections. Thousand Oaks, California: SAGE Publications, Inc., 2000.
Cita MLA (9th ed.)Campbell, James E. and Garand. Before the Vote: Forecasting American National Elections. SAGE Publications, Inc., 2000.
Atenció: Aquestes cites poden no estar 100% correctes.