@article{Angrist1992,
author = {Angrist, J.D. and Krueger, A.B.},
title= {The effect of age at school entry on educational attainment: An application on instrumental variables with moments from two samples},
year = {1992},
doi = {10.1080/01621459.1992.10475212},
journal = {Journal of the American Statistical Association},
volume = {87},
number = {418},
pages = {328--336},
}