@misc{indiciae86caaf57fa12,
  title = {Are letter codes always activated?},
  author = {S N Greenberg},
  year = {1988},
  doi = {10.3758/bf03210414},
  url = {https://pubmed.ncbi.nlm.nih.gov/3226880/},
  note = {Source identifier: 3226880}
}