1. Clinical Obstetrics;Lull,1953
2. Management of Obstetrical Difficulties;Titus,1950
3. Williams' Obstetrics;Eastman,1950
4. Principles and Practices of Obstetrics;Greenhill,1951
5. Extra-uterine pregnancy; lithopedion;Masson;Surg., Gynec. & Obst.,1928