Cita APA (7a ed.)

Callen, P. W., Norton, M. E., & Scoutt, L. M. (2017). Callen's ultrasonography in obstetrics and gynecology (Sixth edition.). Elsevier.

Cita Chicago Style (17a ed.)

Callen, Peter W., Mary E. Norton, y Leslie M. Scoutt. Callen's Ultrasonography in Obstetrics and Gynecology. Sixth edition. Philadelphia, PA: Elsevier, 2017.

Cita MLA (9a ed.)

Callen, Peter W., et al. Callen's Ultrasonography in Obstetrics and Gynecology. Sixth edition. Elsevier, 2017.