@misc{indiciae48dbb5274aed,
  title = {A double-balloon ureteric-stone extractor.},
  author = {J P Williams},
  year = {1969},
  doi = {10.1016/s0140-6736(69)90432-2},
  url = {https://pubmed.ncbi.nlm.nih.gov/4186171/},
  note = {Source identifier: 4186171}
}