Citazione Stile APA (7a Edizione)

Eastman, N., & Hellman, L. M. (1961). Williams Obstetrics (12.ed.). Appleton-Century-Croffts.

Citazione stile Chigago Style (17a edizione)

Eastman, Nicholson, e Louis M. Hellman. Williams Obstetrics. 12.ed. New York: Appleton-Century-Croffts, 1961.

Citatione MLA (9a ed.)

Eastman, Nicholson, e Louis M. Hellman. Williams Obstetrics. 12.ed. Appleton-Century-Croffts, 1961.