@article{Rosenbaum1985,
author = {Rosenbaum, P.R. and Rubin, D.B.},
title= {Constructing a control group using multivariate matched sampling methods that incorporate the propensity score},
year = {1985},
doi = {10.1080/00031305.1985.10479383},
journal = {The American Statistician},
volume = {39},
number = {1},
pages = {33--38},
}