@misc{indiciae30be0caf3703,
  title = {Within-pair differentiation in discrimination learning.},
  author = {R A Champion and C D Standish},
  year = {1967},
  doi = {10.1037/h0025046},
  url = {https://pubmed.ncbi.nlm.nih.gov/6079858/},
  note = {Source identifier: 6079858}
}