@article{Hernán2002,
author = {Hernán, M.A. and Hernández-Diaz, S. and Werler, M.M. and Mitchell, A.A.},
title= {Causal knowledge as a prerequisite for confounding evaluation: an application to birth defects epidemiology},
year = {2002},
doi = {10.1093/aje/155.2.176},
journal = {American Journal of Epidemiology},
volume = {155},
number = {2},
pages = {176--184},
}