@article{Duncan1965,
author = {Duncan, O.D. and Freedman, R.  and Coble, J.M. and Slesinger, D.P.},
title= {Marital fertility and size of family of orientation},
year = {1965},
doi = {10.2307/2060135},
journal = {Demography},
volume = {2},
number = {1},
pages = {508--515},
}