@misc{indiciae8a27d31f440b,
  title = {Marijuana use by heroin abusers as a factor in program retention.},
  author = {M Ellner},
  year = {1977},
  doi = {10.1037//0022-006x.45.4.709},
  url = {https://pubmed.ncbi.nlm.nih.gov/886059/},
  note = {Source identifier: 886059}
}