@misc{indiciae32bfb25107cb,
  title = {Environmental determinants of basic difficulty problems.},
  author = {A J DRUCKER and H H REMMERS},
  year = {1952},
  doi = {10.1037/h0062798},
  url = {https://pubmed.ncbi.nlm.nih.gov/14937977/},
  note = {Source identifier: 14937977}
}