@article{JMLR:v19:14-033,
  author  = {Xu-Qing Liu and Xin-Sheng Liu},
  title   = {Markov Blanket and Markov Boundary of Multiple Variables},
  journal = {Journal of Machine Learning Research},
  year    = {2018},
  volume  = {19},
  number  = {43},
  pages   = {1--50},
  url     = {http://jmlr.org/papers/v19/14-033.html}
}