Xi Bo, Zhou Chengchao, Zhang Min, Wang Yan, Xu Lingzhong
Department of Maternal and Child Health, School of Public Health, Shandong University, Jinan 250012, China.
Department of Social Medicine and Health Management Care, School of Public Health, Shandong University, Jinan, China.
Lancet. 2014 Mar 15;383(9921):953-4. doi: 10.1016/S0140-6736(14)60481-5.