@article{JMLR:v17:16-004,
  author  = {Jiahe Lin and Sumanta Basu and Moulinath Banerjee and George Michailidis},
  title   = {Penalized Maximum Likelihood Estimation of Multi-layered Gaussian Graphical Models},
  journal = {Journal of Machine Learning Research},
  year    = {2016},
  volume  = {17},
  number  = {146},
  pages   = {1--51},
  url     = {http://jmlr.org/papers/v17/16-004.html}
}