Cita APA (7a ed.)

Callen, P. W. (1988). Ultrasonography in obstetrics and gynecology (2nd ed.). Saunders.

Cita Chicago Style (17a ed.)

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 2nd ed. Philadelphia [etc.]: Saunders, 1988.

Cita MLA (9a ed.)

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 2nd ed. Saunders, 1988.