Wadsworth, B. J. (1972). Piaget's theory of cognitive development: An introd. for students of psychology and education (2.print.). McKay.
Chicago-Zitierstil (17. Ausg.)Wadsworth, Barry J. Piaget's Theory of Cognitive Development: An Introd. for Students of Psychology and Education. 2.print. New York: McKay, 1972.
MLA-Zitierstil (9. Ausg.)Wadsworth, Barry J. Piaget's Theory of Cognitive Development: An Introd. for Students of Psychology and Education. 2.print. McKay, 1972.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.