@misc{indiciae1ad031a2a423,
  title = {Nitric oxide--another factor in cervical ripening.},
  author = {A A Calder},
  year = {1998},
  doi = {10.1093/humrep/13.2.250},
  url = {https://pubmed.ncbi.nlm.nih.gov/9557814/},
  note = {Source identifier: 9557814}
}