@article{Dykstra2007,
author = {Dykstra, P.A. and Hagestad, G.O.},
title= {Childlessness and parenthood in two centuries},
year = {2007},
doi = {10.1177/0192513X07303881},
journal = {Journal of Family Issues},
volume = {28},
number = {11},
pages = {1518--1532},
}