Popular- and electoral-vote counts for presidential elections from 1789 to 2012 were obtained from the following sources. Counting the Votes used these counts to calculate the percentages, indexes, and specialized statistics featured on this site.

• Bain, Richard, and Judith Parris. Convention Decisions and Voting Records. Washington: Brookings Institution, 1973.
• Burnham, W. Dean. Presidential Ballots, 1836-1892. Baltimore: Johns Hopkins University Press, 1955.
• Clerk of the House of Representatives. Statistics of the Presidential and Congressional Election. Washington: United States House of Representatives, 1920-2012, quadrennial.
• Cook, Rhodes. United States Presidential Primary Elections, 1968-1996. Washington: CQ Press, 2000.
• Dubin, Michael. United States Presidential Elections, 1788-1860. Jefferson, North Carolina: McFarland & Co., 2002.
• Federal Election Commission. Federal Elections: Election Results for the U.S. President, the U.S. Senate, and the U.S. House of Representatives. Washington: Federal Election Commission, 1985-2013, quadrennial.
• Guide to U.S. Elections. Washington: CQ Press, 2005.
• McGillivray, Alice, and Richard Scammon. America at the Polls, 1920-1956. Washington: Congressional Quarterly, 1994.
• McGillivray, Alice, Richard Scammon, and Rhodes Cook. America at the Polls, 1960-2004. Washington: CQ Press, 2005.
• Petersen, Svend. A Statistical History of the American Presidential Elections. New York: Frederick Ungar, 1963.
• Presidential Elections, 1789-2008. Washington: CQ Press, 2010.
• Robinson, Edgar Eugene. The Presidential Vote, 1896-1932. New York: Octagon, 1970.
• Runyon, John, Jennefer Verdini, and Sally Runyon. Source Book of American Presidential Campaign and Election Statistics, 1948-1968. New York: Frederick Ungar, 1971.
• Scammon, Richard. America at the Polls, 1920-1964. Pittsburgh: University of Pittsburgh Press, 1965.
• Thomas, G. Scott. The Pursuit of the White House. New York: Greenwood, 1987.
• United States Census Bureau. Historical Statistics of the United States, Colonial Times to 1970. Washington: United States Government Printing Office, 1975.
• United States Census Bureau. Statistical Abstract of the United States, 2012. Washington: United States Government Printing Office, 2011.