@article{JMLR:v22:20-1444,
  author  = {Tim van Erven and Wouter M. Koolen and Dirk van der Hoeven},
  title   = {MetaGrad: Adaptation using Multiple Learning Rates in Online Learning},
  journal = {Journal of Machine Learning Research},
  year    = {2021},
  volume  = {22},
  number  = {161},
  pages   = {1--61},
  url     = {http://jmlr.org/papers/v22/20-1444.html}
}