@article{JMLR:v19:16-534,
  author  = {Abhimanyu Das and David Kempe},
  title   = {Approximate Submodularity and its Applications: Subset Selection, Sparse Approximation and Dictionary Selection},
  journal = {Journal of Machine Learning Research},
  year    = {2018},
  volume  = {19},
  number  = {3},
  pages   = {1--34},
  url     = {http://jmlr.org/papers/v19/16-534.html}
}