@misc{indiciae67d66aa55c02,
  title = {Programmed instruction.},
  author = {J M Costello},
  year = {1977},
  doi = {10.1044/jshd.4201.03},
  url = {https://pubmed.ncbi.nlm.nih.gov/839753/},
  note = {Source identifier: 839753}
}