@misc{indiciae8848225fc035,
  title = {Some difficulties with difficulty: note on Horst's "Mattrix Factoring and Test Theory".},
  author = {M C Corballis},
  year = {1968},
  doi = {10.2466/pr0.1968.22.1.15},
  url = {https://pubmed.ncbi.nlm.nih.gov/5641202/},
  note = {Source identifier: 5641202}
}