Cita APA (7a ed.)

Callen, P. W. (1994). Ultrasonography in obstetrics and gynecology (3rd ed.). Saunders.

Cita Chicago Style (17a ed.)

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 3rd ed. Philadelphia [etc.]: Saunders, 1994.

Cita MLA (9a ed.)

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 3rd ed. Saunders, 1994.