@misc{indiciae2d7c19f993f1,
  title = {Concept formation: a problem in human operant conditioning.},
  author = {E J GREEN},
  year = {1955},
  doi = {10.1037/h0048778},
  url = {https://pubmed.ncbi.nlm.nih.gov/14367692/},
  note = {Source identifier: 14367692}
}