@article{7:58,author={Shai Shalev-Shwartz and Yoram Singer}, Title={Efficient Learning of Label Ranking by Soft Projections onto Polyhedra (Special Topic on Machine Learning and Optimization)},journal={Journal of Machine Learning Research},volume={7}, url={http://www.jmlr.org/papers/volume7/shalev-shwartz06a/shalev-shwartz06a.pdf}}