Cita APA (7th ed.)

Sigel, I. E., & Hooper, F. H. (1968). Logical thinking in children: Research based on Piaget's theory. Holt, Rinehart and Winston.

Cita Chicago (17th ed.)

Sigel, Irving E., i Frank H. Hooper. Logical Thinking in Children: Research Based on Piaget's Theory. New York: Holt, Rinehart and Winston, 1968.

Cita MLA (9th ed.)

Sigel, Irving E., i Frank H. Hooper. Logical Thinking in Children: Research Based on Piaget's Theory. Holt, Rinehart and Winston, 1968.