@article{11:39,author={Jin Yu and S.V.N. Vishwanathan and Simon Gunter and Nicol N. Schraudolph}, Title={A Quasi-Newton Approach to Nonsmooth Convex Optimization Problems in Machine Learning},journal={Journal of Machine Learning Research},volume={11}, url={http://www.jmlr.org/papers/volume11/yu10a/yu10a.pdf}}