@misc{indiciae9782b0dcdd9c,
  title = {Inducing a preference for morphine in rats without premedication.},
  author = {R Kumar and H Steinberg and I P Stolerman},
  year = {1968},
  doi = {10.1038/218564a0},
  url = {https://pubmed.ncbi.nlm.nih.gov/5689915/},
  note = {Source identifier: 5689915}
}