@techreport{Ross1974,
author = {Ross, S.G.},
title= {The timing and spacing of births and women’s labor force participation: An economic analysis},
year = {1974},
URL = {http://www.nber.org/papers/w0030},
publisher = {National Bureau of Economic Research},
address = {Cambridge, MA},
number = {(NBER Working Paper No. 30)},
}