Gaya APA

Callen, P, W. (2008). Ultrasonography in Obstetrics and Gynecology (5th). North America: Saunders Elsevier.

Gaya MLA

Callen, Peter, W.. "Ultrasonography in Obstetrics and Gynecology". 5th North America: Saunders Elsevier, 2008. Teks (Text).