1. The Barton Obstetric Forceps—A review of its use in fifty five cases;Bachman;Surgery, Gynecology & Obstetrics,1927
2. The Ventouse;Chalmers,1971
3. Use of a vacuum extractor (ventouse) in obstetrics;Chalmers;British Medical Journal,1960
4. Five years experience with the vacuum extrator;Chalmers;British Medical Journal,1964
5. Principles and Practice of Obstetrics;de Lee,1947