1. Experimental and quasi-experimental designs for research;Campbell,1966
2. Meta-analysis in social research;Glass,1981
3. Evaluation: The state of the art and the sorry slate of the science;Lipsey;New Directions for Program Evaluation,1985
4. Mela-analytic procedures for social research;Rosenthal,1984
5. A simple, general purpose display of magnitude of experimental effect;Rosenthal;Journal of Educational Psychology,1982