@misc{indiciaec0810fa72a05,
  title = {Effects of concurrent schedules on human fixed-interval performance.},
  author = {R Poppen},
  year = {1972},
  doi = {10.1901/jeab.1972.18-119},
  url = {https://pubmed.ncbi.nlm.nih.gov/16811607/},
  note = {Source identifier: 16811607}
}