1. Alexander, K. L., Entwisle, D. R., & Dauber, S. L. (1994). On the success of failure: A reassessment of the effects of retention in the primary grades. New York: Cambridge University Press.
2. Alexander, K. L., Entwisle, D. R., & Dauber, S. L. (2003). On the success of failure: A reassessment of the effects of retention in the primary grades (2nd ed.). New York: Cambridge University Press.
3. Campbell, D. T., & Kenny, D. A. (1999). A primer on regression artifacts. New York: Guilford Press.
4. Campbell, D. T., & Stanley, J. C. (1966). Experimental and quasi-experimental designs for research. Chi cago: Rand McNally.
5. Chansky, N. M. (1964). Progress of promoted and repeating grade 1 failures. Journal of Experimental Education, 32(3), 225–237.