@article{Bongaarts1979,
author = {Bongaarts, J. and Potter, R.G.},
title= {Fertility effect of seasonal migration and seasonal variation in fecundability: Test of a useful approximation under more general conditions},
year = {1979},
doi = {10.2307/2061226},
journal = {Demography},
volume = {16},
number = {3},
pages = {475--479},
}