1. A B C's of Community Planning (Chicago, Illinois: The Community Planning Division of Sears, Roebuck & Co. 1-62), p. 13.
2. Planning With Principles
3. Brunner, Edmund des., et al. An Overview of Adult Education Research ( Washington, D. C.: Adult Education Association of the U.S.A., 1959), p. 125.
4. Buxton, C.E. "The Frame of Reference," Fields of Psychology, ed. by R. H. Seashore (New York: Holt, 1942), p. 17.