@article {Heiler-Schnoerr-06b,
	title = {Learning Sparse Representations by Non-Negative Matrix Factorization and Sequential Cone Programming},
	journal = {J.~Mach.~Learning Res.},
	volume = {7},
	year = {2006},
	pages = {1385--1407},
	url = {http://www.cvgpr.uni-mannheim.de/Publications}
}
