@misc{indiciaeeef36bcf2318,
  title = {A guide to interpreting contraceptive efficacy studies.},
  author = {J Trussell and R A Hatcher and W Cates and F H Stewart and K Kost},
  year = {1990},
  url = {https://pubmed.ncbi.nlm.nih.gov/2199875/},
  note = {Source identifier: 2199875}
}