@article{Roodman2009,
author = {Roodman, D.},
title= {A note on the theme of too many instruments},
year = {2009},
doi = {10.1111/j.1468-0084.2008.00542.x},
journal = {Oxford Bulletin of Economics and Statistics},
volume = {71},
number = {1},
pages = {135--158},
}