@article {540676,
	title = {HarvardX and MITx: Two years of Open Online Courses Fall 2012-Summer 2014},
	journal = {HarvardX Working Paper},
	year = {2015},
	url = {http://ssrn.com/abstract=2586847},
	author = {Andrew Dean Ho and Isaac Chuang and Justin Reich and Coleman, Cody Austun and Whitehill, Jacob and Northcutt, Curtis G. and Williams, Joseph Jay and Hansen, John D. and Lopez, Glenn and Petersen, Rebecca}
}
