Data comes from 17,700 interviews from twelve NORC surveys from 1963 to 1974. Andrew Greeley, Ethnicity, denomination and inequality (Sage Research Papers in the Social Sciences. #90-029 volume 4, 1976) pp. 13, 24. online
Mare, Robert D. (1991-01-01). "Five Decades of Educational Assortative Mating". American Sociological Review. 56 (1): 15–32. doi:10.2307/2095670. JSTOR2095670.
Mare, Robert D. (1991-01-01). "Five Decades of Educational Assortative Mating". American Sociological Review. 56 (1): 15–32. doi:10.2307/2095670. JSTOR2095670.
Robert Bruce Mullin, "Trends in the Study of the History of the Episcopal Church". Anglican and Episcopal History 72#2 (2003), pp. 153–65. online
Bradley J. Longfield, "Presbyterianism and American Culture," Journal of Presbyterian History 84#1 (2006) pp. 28-36. online