International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project

José Villar, Leila Cheikh Ismail, César G. Victora, Eric O. Ohuma, Enrico Bertino, Doug Altman, Ann Lambert, Aris T. Papageorghiou, Maria Carvalho, Yasmin A. Jaffer, Michael G. Gravett, Manorama Purwar, Ihunnaya O. Frederick, J. Alison Noble, Ruyan Pang, Fernando C. Barros, Cameron Chumlea, Zulfiqar A Bhutta, Stephen Kennedy