@misc{indiciae8326b50b0277,
  title = {Human choice on concurrent variable-interval variable-ratio schedules.},
  author = {A Silberberg and J R Thomas and N Berendzen},
  year = {1991},
  doi = {10.1901/jeab.1991.56-575},
  url = {https://pubmed.ncbi.nlm.nih.gov/1774545/},
  note = {Source identifier: 1774545}
}