@misc{indiciaec56cf7266191,
  title = {Pharmacologically active I.U.D.s.},
  author = {D Wolfers},
  year = {1972},
  doi = {10.1136/bmj.1.5792.112-a},
  url = {https://pubmed.ncbi.nlm.nih.gov/5007062/},
  note = {Source identifier: 5007062}
}