APA (7th ed.) Citation

Callen, P. W. (1988). Ultrasonography in obstetrics and Gynecology.

Chicago Style (17th ed.) Citation

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 1988.

MLA (9th ed.) Citation

Callen, Peter W. Ultrasonography in Obstetrics and Gynecology. 1988.

Warning: These citations may not always be 100% accurate.