Sigel, I. E., Hooper, F. H., & Piaget, J. (1968). Logical thinking in children: Research based on Piaget's theory. Holt, Rinehart and Winston.
Chicago Style (17th ed.) CitationSigel, Irving E., Frank H. Hooper, and Jean Piaget. Logical Thinking in Children: Research Based on Piaget's Theory. New York: Holt, Rinehart and Winston, 1968.
MLA (9th ed.) CitationSigel, Irving E., et al. Logical Thinking in Children: Research Based on Piaget's Theory. Holt, Rinehart and Winston, 1968.
Warning: These citations may not always be 100% accurate.