@misc{indiciaed85a17a55782,
  title = {Correct visualization of the anal ring.},
  author = {S C Thornton and S A Hirshorn and M Bradway and D Levien},
  year = {2001},
  doi = {10.1097/00004836-200110000-00024},
  url = {https://pubmed.ncbi.nlm.nih.gov/11588559/},
  note = {Source identifier: 11588559}
}