1. Operative vaginal delivery—year 2000;Hankins;Am J Obstet Gynecol,1996
2. Validation of the 1988 ACOG forceps classification system;Hagadorn-Freathy;Obstet Gynecol,1991
3. A randomized comparison of assisted vaginal delivery by obstetric forceps and polyethylene vacuum cup;Williams;Obstet Gynecol,1991
4. Survey of forceps training in North America in 1981;Healy;Am J Obstet Gynecol,1985
5. Survey of forceps delivery in North America in 1990;Ramin;Obstet Gynecol,1993