Gruber, H. E. (1977). The essential Piaget. New York (N.Y.): Basic Books.
Chicago Style CitationGruber, Howard E. The Essential Piaget. New York (N.Y.): Basic Books, 1977.
MLA CitationGruber, Howard E. The Essential Piaget. New York (N.Y.): Basic Books, 1977.
Warning: These citations may not always be 100% accurate.