@misc{indiciaeeb4226795897,
  title = {Token economy systems: breakdown and control.},
  author = {J Hall and R Baker},
  year = {1973},
  doi = {10.1016/0005-7967(73)90001-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/4727289/},
  note = {Source identifier: 4727289}
}