BibTex format
@article{Joffe:2012:10.1186/1742-7622-9-1,
author = {Joffe, M and Gambhir, M and Chadeau-Hyam, M and Vineis, P},
doi = {10.1186/1742-7622-9-1},
journal = {Emerging Themes in Epidemiology},
title = {Causal diagrams in systems epidemiology},
url = {http://dx.doi.org/10.1186/1742-7622-9-1},
volume = {9},
year = {2012}
}