1. Self-perception: An alternative explanation of cognitive dissonance phenomena;Bem;Psychological Review,1967
2. Causal inference in nonexperimental research;Blalock,1964
3. The measurement problem: A gap between the language of theory and research;Blalock,1968
4. Observations on the measurement of change;Bohrnstedt,1969
5. Experimental and quasi-experimental designs for research on teaching;Campbell,1963