@article{Butz1979,
author = {Butz, W.P. and Ward, M.P.},
title= {The Emergence of Countercyclical U.S. Fertility},
year = {1979},
doi = {10.2307/1807367},
journal = {The American Economic Review},
volume = {69},
number = {3},
pages = {318--328},
}