Cita APA (7th ed.)

Willis, S. L., & Schaie, K. W. (2021). Handbook of the psychology of aging (Ninth edition.). Academic Press, an imprint of Elsevier.

Cita Chicago (17th ed.)

Willis, Sherry L., i K. Warner Schaie. Handbook of the Psychology of Aging. Ninth edition. London, United Kingdom: Academic Press, an imprint of Elsevier, 2021.

Cita MLA (9th ed.)

Willis, Sherry L., i K. Warner Schaie. Handbook of the Psychology of Aging. Ninth edition. Academic Press, an imprint of Elsevier, 2021.