@misc{indiciae6438eb506061,
  title = {Spaced responding and choice: a preliminary analysis.},
  author = {J E Staddon},
  year = {1968},
  doi = {10.1901/jeab.1968.11-669},
  url = {https://pubmed.ncbi.nlm.nih.gov/16811314/},
  note = {Source identifier: 16811314}
}