@article {xu2014sparse,
	title = {The Sparse MLE for Ultrahigh-Dimensional Feature Screening},
	journal = {Journal of the American Statistical Association},
	volume = {109},
	number = {507},
	year = {2014},
	pages = {1257{\textendash}1269},
	publisher = {Taylor \& Francis},
	author = {Xu, Chen and Chen, Jiahua}
}
