@misc{indiciae87d787dabeba,
  title = {Preference for qualitatively different reinforcers.},
  author = {V Hollard and M C Davison},
  year = {1971},
  doi = {10.1901/jeab.1971.16-375},
  url = {https://pubmed.ncbi.nlm.nih.gov/16811552/},
  note = {Source identifier: 16811552}
}