Lancet Global Health
Jan 2019   Volume 7  Number 1e1-e159
http://www.thelancet.com/journals/langlo/issue/current

Articles
Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis
Saifon Chawanpaiboon, Joshua P Vogel, Ann-Beth Moller, Pisake Lumbiganon, Max Petzold,
Daniel Hogan, Sihem Landoulsi, Nampet Jampathong, Kiattisak Kongwattanakul, Malinee Laopaiboon, Cameron Lewis, Siwanon Rattanakanokchai, Ditza N Teng, Jadsada Thinkhamrop,
Kanokwaroon Watananirun, Jun Zhang, Wei Zhou, A Metin Gülmezoglu