@misc{indiciae6a564345112e,
  title = {Strict and random alternation in concurrent variable-interval schedules.},
  author = {Douglas Elliffe and Michael Davison},
  year = {2003},
  doi = {10.1901/jeab.2003.79-65},
  url = {https://pubmed.ncbi.nlm.nih.gov/12696742/},
  note = {Source identifier: 12696742}
}