@article{Imbens1994,
author = {Imbens, G. and Angrist, J.},
title= {Identification and estimation of local average treatment effects},
year = {1994},
doi = {10.2307/2951620},
journal = {Econometrica: Journal of the Econometric Society},
volume = {62},
number = {2},
pages = {467−475},
}