Citazione Stile APA (7a Edizione)

CALLEN, P. W. (2000). Ultrasonography in obstetrics and gynecology.-- ed.4. W.B. Saunders Company.

Citazione stile Chigago Style (17a edizione)

CALLEN, Peter W. Ultrasonography in Obstetrics and Gynecology.-- Ed.4. Philadelphia: W.B. Saunders Company, 2000.

Citatione MLA (9a ed.)

CALLEN, Peter W. Ultrasonography in Obstetrics and Gynecology.-- Ed.4. W.B. Saunders Company, 2000.