1. Agger, R.E. (1959) "Independents and party identifiers: characteristics and behavior in 1952," pp. 308-329 in E. Burdick and A. J. Brodbeck (eds.) American Voting Behavior. New York: Free Press.
2. Converse, P. (1966) "Religion and politics: the 1960 election," pp. 96-124in A. Campbell et al. Elections and the Political Order. New York: John Wiley.