Pezzulo C,Nilsen K, Carioli A, Tejedor-aravito N, Hanspal SE, Hilber T, James, WHM, Ruktanonchai CW, Alegana VA, Sorichetta A, Wigley AS, Hornby GM, Matthews Z, Tatem AJ(2021). Geographical distribution of fertility rates in 70 low-income, lower-middle-income, and upper-middle-income countries, 2010–16: a subnational analysis of cross-sectional surveys. Lancet Glob Health. 9:e802-12 .[PMCID: 8149299] ,[PMID: 34019836]