Eastman, N., & Hellman, L. M. (1961). Williams Obstetrics.
芝加哥风格引文Eastman, Nicholson, 与 Louis M. Hellman. Williams Obstetrics. 1961.
MLA引文Eastman, Nicholson, 与 Louis M. Hellman. Williams Obstetrics. 1961.
警告：这些引文格式不一定是100％准确.
APA引文