Citazione Stile APA (7a Edizione)

Williams, J. W., Hellman, L. M., & Pritchard, J. A. 1. (1971). Williams obstetrics (14th ed.). Appleton-Century-Crofts.

Citazione stile Chigago Style (17a edizione)

Williams, J. Whitridge, Louis M. Hellman, e Jack A. 11921- Pritchard. Williams Obstetrics. 14th ed. New York: Appleton-Century-Crofts, 1971.

Citatione MLA (9a ed.)

Williams, J. Whitridge, et al. Williams Obstetrics. 14th ed. Appleton-Century-Crofts, 1971.