1. Quantity Conceptions in College Students
2. The Relationship Between an Inquiry Teaching Approach and Intellectual Development, Unpublished Doctoral Dissertation, University of Oklahoma, 1970.
3. and , Elusiveness of Formal Operational Thought in Adolescents, Proceedings 79th Annual Convention APA, 201–202. (1971).
4. Criteria of the Stages of Mental Development, In and , (Eds.) Psychological Studies of Human Development, New York, Appleton-Century-Crofts, 1970.