@inproceedings{sparseinversecovariancematrixestimation,
  title = {Sparse Inverse Covariance Matrix Estimation Using Quadratic Approximation},
  author = {Cho-Jui Hsieh and Matyas A. Sustik and Inderjit S. Dhillon and Pradeep Ravikumar},
  year = {2013},
  booktitle = {NeurIPS 2011 12},
  eprint = {1306.3212},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1306.3212v1},
}