Arnak S. Dalalyan Anatoli Juditsky Vladimir Spokoiny A New Algorithm for Estimating the Effective Dimension-Reduction Subspace. 1647-1678 2008 9 Journal of Machine Learning Research http://doi.acm.org/10.1145/1390681.1442786 db/journals/jmlr/jmlr9.html#DalalyanJS08