@inproceedings{simplestatisticalgradientfollowing,
  title = {Simple Statistical Gradient-Following Algorithms for Connectionist Reinforcement Learning},
  author = {Ronald J. Williams},
  year = {1992},
  booktitle = {Machine Learning 1992 5},
  url = {https://link.springer.com/article/10.1007/BF00992696},
}