1. The relationship between class absences and college grades.
2. School Achievement and Attendance
3. Campbell, D. T. From Description to Experimentation: Interpreting Trends as Quasi-experiments. In C. W. Harris, (Ed.) Problems in Measuring Change. Madison, Wisconsin: University of Wisconsin Press , 1963, pp. 212-242.
4. Campbell, D. T. and Stanley, J. C. 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.