Eastman, N., & Hellman, L. M. (1961). Williams Obstetrics.
Cita Chicago (17th ed.)Eastman, Nicholson, i Louis M. Hellman. Williams Obstetrics. 1961.
Cita MLA (9th ed.)Eastman, Nicholson, i Louis M. Hellman. Williams Obstetrics. 1961.
Atenció: Aquestes cites poden no estar 100% correctes.