Campbell, D. T. and Clayton, K. N.Avoiding regression effects in panel studies of communication impact. Studies in Public Communication, University of Chicago Press, 1961, No. 3, 99-118.
2.
Campbell, D. T. and Stanley, J. S.Experimental and quasi-experimental designs for research on teaching. In N. L. Gage (Ed.), Handbook of research on teaching. Chicago: Rand McNally, 1963, pp. 171-246.
3.
Evans, S. H. and Anastasio, E. J.Misuse of analysis of covariance when treatment effect and covariate are confounded. Psychological Bulletin, 1968, 69, 225-234.
4.
Lord, F. M.A paradox in the interpretation of group comparisons. Psychological Bulletin, 1967, 68, 304-305.
5.
Schaie, K. W.A general model for the study of developmental problems. Psychological Bulletin, 1965, 64, 92-107.
6.
Winer, B. J.Statistical principles in experimental design. New York: McGraw-Hill, 1962, Chapter 7.
