1. American Association for the Advancement of Science. Science-A Process Approach, Parts A, B, C, and D. Blauvelt, N. Y.: Xerox Corporation, 1968.
2. The relative effectiveness of stereometric and pattern stimuli in discrimination learning in children
3. Elementary Science Study. Attribute games and problems. Newton, Mass.: Educational Development Corporation, 1966.
4. Principles of perceptual learning and development. New York: Appleton-Century-Crofts, 1969, 397.
5. What is form. Psychological Review, No. 58, 1951, (58) 405.