@article{Yang2007,
author = {Yang, Q. and Wen, S.W. and Leader, A. and Chen, X.K. and Lipson, J. and Walker, M.},
title= {Paternal age and birth defects: How strong is the association?},
year = {2007},
doi = {10.1093/humrep/del453},
journal = {Human Reproduction},
volume = {22},
number = {3},
pages = {696--701},
}