National, regional, and worldwide estimates of low birthweight in 2015, with trends from 2000: a systematic analysis oleh Hannah Blencowe, MRCPCH, Julia Krasevec, MSc, Mercedes de Onis, MD, Robert E Black, ProfMD, Xiaoyi An, MA, Gretchen A Stevens, DSc, Elaine Borghi, PhD, Chika Hayashi, PhD, Diana Estevez, MSc, Luca Cegolon, MD, Suhail Shiekh, MSc, Victoria Ponce Hardy, MSc, Joy E Lawn, ProfFRCPCH, Simon Cousens, ProfDipMathstat