@misc{indiciae40b32e7b4819,
  title = {Timeout and concurrent fixed-ratio schedules with human subjects.},
  author = {S Striefel},
  year = {1972},
  doi = {10.1901/jeab.1972.17-213},
  url = {https://pubmed.ncbi.nlm.nih.gov/16811583/},
  note = {Source identifier: 16811583}
}