Wadsworth, B. J. (1977). Piaget's theory of cognitive development: An introduction for students of psychology and education (8. print.). Longman.
Chicago-Zitierstil (17. Ausg.)Wadsworth, Barry J. Piaget's Theory of Cognitive Development: An Introduction for Students of Psychology and Education. 8. print. New York, NY: Longman, 1977.
MLA-Zitierstil (9. Ausg.)Wadsworth, Barry J. Piaget's Theory of Cognitive Development: An Introduction for Students of Psychology and Education. 8. print. Longman, 1977.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.