APA (7th ed.) Citation

Ames, L. B., & Ilg, F. L. (1984). Your three year old. Piatkus.

Chicago Style (17th ed.) Citation

Ames, Louise Bates, and Frances L. Ilg. Your Three Year Old. London: Piatkus, 1984.

MLA (9th ed.) Citation

Ames, Louise Bates, and Frances L. Ilg. Your Three Year Old. Piatkus, 1984.