@inbook{Cai2007,
author = {Cai, Y. and Lavely, W.},
title= {Child sex ratios and their regional variation},
year = {2007},
doi = {10.1093/acprof:oso/9780199299294.003.0007},
editor = {Zhao, Z.},
editor = {Fei, G.},
booktitle = {Transition and challenge: China’s population at the beginning of the 21st century},
address = {New York},
publisher = {Oxford University Press},
}