Cita APA (7a ed.)

Williams, J. W., & Cunningham, F. G. (1997). Williams obstetrics (20th ed.). Prentice-Hall International.

Cita Chicago Style (17a ed.)

Williams, J. Whitridge, y F. Gary Cunningham. Williams Obstetrics. 20th ed. London: Prentice-Hall International, 1997.

Cita MLA (9a ed.)

Williams, J. Whitridge, y F. Gary Cunningham. Williams Obstetrics. 20th ed. Prentice-Hall International, 1997.