@misc{indiciae142047b7f141,
  title = {Choice between fixed-interval schedules: Graded versus step-like choice functions.},
  author = {R L Shull},
  year = {1992},
  doi = {10.1901/jeab.1992.58-37},
  url = {https://pubmed.ncbi.nlm.nih.gov/16812665/},
  note = {Source identifier: 16812665}
}