Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys.
Vogel JP, Betrán AP, Vindevoghel N, Souza JP, Torloni MR, Zhang J, Tunçalp Ö, Mori R, Morisaki N, Ortiz-Panozo E, Hernandez B, Pérez-Cuevas R, Qureshi Z, Gülmezoglu AM, Temmerman M, WHO Multi-Country Survey on Maternal and Newborn Health Research Network