@article{Greenland2002,
author = {Greenland, S. and Brumback, B.},
title= {An overview of relations among causal modelling methods},
year = {2002},
doi = {10.1093/ije/31.5.1030},
journal = {International Journal of Epidemiology},
volume = {31},
number = {5},
pages = {1030--1037},
}