@article{Bille2005,
author = {Bille, C. and Skytthe, A. and Vach, W. and Knudsen, L.B. and Andersen, A.M. and Murray, J.C. and Christensen, K.},
title= {Parent’s age and the risk of oral clefts},
year = {2005},
doi = {10.1097/01.ede.0000158745.84019.c2},
journal = {Epidemiology},
volume = {16},
number = {3},
pages = {311--316},
}