@misc{indiciae1569d1a241ad,
  title = {A stimulating environment},
  author = {W.H. Bradley},
  year = {1963},
  doi = {10.1126/science.141.3576.232-a},
  url = {https://pubs.usgs.gov/publication/70219984},
  note = {Source identifier: 70219984}
}