APA
Wadsworth B. J., . (1971). Piaget's theory of cognitive and effective development. New York: Longman.
Chicago
Wadsworth Barry J, . 1971. Piaget's theory of cognitive and effective development. New York: Longman.
Harvard
Wadsworth B. J., . (1971). Piaget's theory of cognitive and effective development. New York: Longman.
MLA
Wadsworth Barry J, . Piaget's theory of cognitive and effective development. New York: Longman. 1971.