@article{Urquiola&VerhoogenAER2009,
	author = {Miguel S. Urquiola and Eric A. Verhoogen},
	title = {Class-Size Caps, Sorting, and the Regression Discontinuity Design},
	journal = {American Economic Review},
	year = {2009},
	volume = {99},
	number = {1},
	pages = {179-215},

}