@article{Grech2002,
author = {Grech, V. and Savona-Ventura, C. and Vassallo-Agius, P.},
title= {Unexplained differences in sex ratios at birth in Europe and North America},
year = {2002},
doi = {10.1136/bmj.324.7344.1010},
volume = {324},
number = {7344},
pages = {1010--1011},
}