@book{66848,
	author = {Ginsburg, Herbert. and Opper, Sylvia.},
	title = {Piaget's theory of intellectual development /},
	publisher = {Prentice-Hall,},
	year = {c1988.},
	address = {Englewood Cliffs, N.J. :},
	edition = {3rd ed.},
	note = {Includes index.}
}