Citazione Stile APA (7a Edizione)

Beard, R. M. (1969). An outline of Piaget's developmental psychology for students and teachers. Routledge & Kegan Paul.

Citazione stile Chigago Style (17a edizione)

Beard, Ruth M. An Outline of Piaget's Developmental Psychology for Students and Teachers. Londres: Routledge & Kegan Paul, 1969.

Citatione MLA (9a ed.)

Beard, Ruth M. An Outline of Piaget's Developmental Psychology for Students and Teachers. Routledge & Kegan Paul, 1969.