@misc{indiciae3fcc9d0edad1,
  title = {Operant behavior in mental defectives: exploratory studies.},
  author = {N R ELLIS and C D BARNETT and M W PRYER},
  year = {1960},
  doi = {10.1901/jeab.1960.3-63},
  url = {https://pubmed.ncbi.nlm.nih.gov/13820047/},
  note = {Source identifier: 13820047}
}