@article{multilevelcompositestochasticoptimizatio,
  title = {Multi-Level Composite Stochastic Optimization via Nested Variance Reduction},
  author = {Junyu Zhang and Lin Xiao},
  year = {2019},
  eprint = {1908.11468},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/1908.11468v2},
}