Cita APA (7a ed.)

Eastman, N. J., & Hellman, L. (1966). Williams obstetrics (13th ed.). Appleton-Century-Crofts.

Cita Chicago Style (17a ed.)

Eastman, Nicholson J., y Louis Hellman. Williams Obstetrics. 13th ed. New York: Appleton-Century-Crofts, 1966.

Cita MLA (8a ed.)

Eastman, Nicholson J., y Louis Hellman. Williams Obstetrics. 13th ed. Appleton-Century-Crofts, 1966.