Cita APA (7th ed.)

Beard, R. M. (2006). An outline of Piaget's development psychology. Routledge.

Cita Chicago (17th ed.)

Beard, Ruth M. An Outline of Piaget's Development Psychology. London: Routledge, 2006.

Cita MLA (9th ed.)

Beard, Ruth M. An Outline of Piaget's Development Psychology. Routledge, 2006.