APA

Piaget J., Vonèche J. J. & Gruber H. E. (1977). The essential Piaget. New York: Basic Books.

Chicago

Piaget Jean, Vonèche J Jacques and Gruber Howard E. 1977. The essential Piaget. New York: Basic Books.

Harvard

Piaget J., Vonèche J. J. and Gruber H. E. (1977). The essential Piaget. New York: Basic Books.

MLA

Piaget Jean, Vonèche J Jacques and Gruber Howard E. The essential Piaget. New York: Basic Books. 1977.