@misc{indiciaea4480fb50880,
  title = {A cumulative recorder for student use.},
  author = {P Van Sommers},
  year = {1967},
  doi = {10.1901/jeab.1967.10-299},
  url = {https://pubmed.ncbi.nlm.nih.gov/6056802/},
  note = {Source identifier: 6056802}
}