@misc{indiciaef7ebb9630d8f,
  title = {Operandum.},
  author = {B F SKINNER},
  year = {1962},
  doi = {10.1901/jeab.1962.5-224},
  url = {https://pubmed.ncbi.nlm.nih.gov/13913635/},
  note = {Source identifier: 13913635}
}