@article{JMLR:v21:19-764,
  author  = {Xiao-Tong Yuan and Ping Li},
  title   = {On Convergence of Distributed Approximate Newton Methods: Globalization, Sharper Bounds and Beyond},
  journal = {Journal of Machine Learning Research},
  year    = {2020},
  volume  = {21},
  number  = {206},
  pages   = {1--51},
  url     = {http://jmlr.org/papers/v21/19-764.html}
}