Differences in Child Mortality among Social, Economic, and Residential Groups

Samuel H. Preston and Michael R. Haines, Fatal Years: Child Mortality in Late Nineteenth-Century America (Princeton University Press, 1991), chap. 3, https://www.nber.org/books-and-chapters/fatal-years-child-mortality-late-nineteenth-century-america/differences-child-mortality-among-social-economic-and-residential-groups.