1. Fritz Redl and William W. Wattenberg.Mental Hygiene in Teaching ., Second edition. New York : Harcourt, Brace and Company , 1959 . p. 197 .
2. Educational Policies Commission.The Central Purpose of American Education.Washington , D.C. : National Education Assn. , 1961 , p. 12 .
3. Education Policies Commission ,op. cit.p. 4 .
4. Ibid., p. 16 .