1. Contemporary cesarean delivery practice in the United States;J Zhang;Am J Obstet Gynecol,2010
2. Births: Final Data for 2014;E Brandy;Nat Vital Stat Rep,2015
3. Distribución de la actividad obstétrica realizada en los hospitales según la finalidad de los mismos,2014
4. Variation in elective primary cesarean delivery by patient and hospital factors;KD Gregory;Am J Obstet Gynecol,2001
5. Methodology Medical Practice Variations in the utilization of low-value interventions;S García-Armesto,2016