@article{Funk2011,
author = {Funk, M.J. and Westreich, D. and Wiesen, C. and Stürmer, T. and Brookhart, M.A. and Davidian, M.},
title= {Doubly robust estimation of causal effects},
year = {2011},
doi = {10.1093/aje/kwq439},
volume = {173},
number = {7},
pages = {761--767},
}