@article{article0620116e,
title   = {Outcomes of non-vertex second twins, following vertex vaginal delivery of first twin: a secondary analysis of the WHO Global survey on maternal and perinatal health},
author = {Vogel, Joshua P. and Holloway, Erica and Cuesta, Cristina and Carroli, Guillermo and Souza, João Paulo and Barrett, Jon},
year = {2014},
doi = {10.1186/1471-2393-14-55},
journal   = {BMC Pregnancy and Childbirth}
}