Gregory K, Korst L, Platt L. Variation in elective primary cesarean rates by hospital organizational factors. American Journal of Obstetrics and Gynecology 2001; 184:1521-34.
Martin JA, Hamilton BE, Ventura SJ, et al. Births: Final Data for 2000. National Vital Statistics Reports; vol. 50 No. 5. Hyattsville, MD: National Center for Health Statistics, 2002.