APA (7th ed.) Citation

Piaget, J., Ackermann, E., & Feider, H. (1987). Possibility and necessity. University of Minnesota Press.

Chicago Style (17th ed.) Citation

Piaget, Jean, Edith Ackermann, and Helga Feider. Possibility and Necessity. Minneapolis: University of Minnesota Press, 1987.

MLA (9th ed.) Citation

Piaget, Jean, et al. Possibility and Necessity. University of Minnesota Press, 1987.