References
- Coale , Ansley J. and Zelnik , Melvin . 1963 . New Estimates of Fertility and Population in the United States , Princeton : Princeton University Press .
- Davis , George . 1856 . A Historical Sketch of Sturbridge and Southbridge , West Brookfield, Massachusetts : O. S. Cooke and Co. .
- Wrigley , E. A. 1966 . Introduction to English Historical Demography , New York : Basic Books .
- Henry , Louis . 1961 . Some Data on Natural Fertility . Eugenics Quarterly , 8 June