@misc{indiciae85bcfe9567be,
  title = {Distribution of response ratios in concurrent variable-interval performance.},
  author = {R D Tustin and M C Davison},
  year = {1978},
  doi = {10.1901/jeab.1978.29-561},
  url = {https://pubmed.ncbi.nlm.nih.gov/16812078/},
  note = {Source identifier: 16812078}
}