@misc{indiciaeb0054e64ec9d,
  title = {Token reinforcement systems.},
  author = {G Andrews},
  year = {1971},
  doi = {10.3109/00048677109159636},
  url = {https://pubmed.ncbi.nlm.nih.gov/5289339/},
  note = {Source identifier: 5289339}
}