Cita APA (7th ed.)

Willemsen, E. W., & Nicholson, L. (1979). Understanding infancy. Freeman.

Cita Chicago (17th ed.)

Willemsen, Eleanor Walker, i Louise Nicholson. Understanding Infancy. San Francisco: Freeman, 1979.

Cita MLA (9th ed.)

Willemsen, Eleanor Walker, i Louise Nicholson. Understanding Infancy. Freeman, 1979.