Cita APA (7a ed.)
Ginsburg, H., & Opper, S. (1969). Piaget's theory of intellectual development: An introd. Prentice Hall.
Cita Chicago Style (17a ed.)
Ginsburg, Herbert, y Sylvia Opper. Piaget's Theory of Intellectual Development: An Introd. Englewood cliffs, USA: Prentice Hall, 1969.
Cita MLA (9a ed.)
Ginsburg, Herbert, y Sylvia Opper. Piaget's Theory of Intellectual Development: An Introd. Prentice Hall, 1969.
Precaución: Estas citas no son 100% exactas.