@misc{indiciae33c79f896172,
  title = {Sign learning as a factor in extinction.},
  author = {J P SEWARD and N LEVY},
  year = {1949},
  doi = {10.1037/h0060914},
  url = {https://pubmed.ncbi.nlm.nih.gov/15391109/},
  note = {Source identifier: 15391109}
}