REFERENCES
- EGBERT, ROBERT L. “Planned variation in Follow Through.” Paper delivered before the Brookings Institution Panel on Social Experimentation, Washington, D.C., April 1973.
- STEBBINS, LINDA B., St PIERRE, ROBERT G., PROPER, ELIZABETH C., ANDERSON, RICHARD B., CERVA, THOMAS R., and KENNEDY, MARY M. Education as experimentation: A planned variation model. Vol. 4-A. Cambridge, Mass: Abt Associates, 1977.