@misc{indiciae007ed336bf18,
  title = {Frameless navigation and endoscopy.},
  author = {O Alberti and T Riegel and D Hellwig and H Bertalanffy},
  year = {2001},
  doi = {10.3171/jns.2001.95.3.0541a},
  url = {https://pubmed.ncbi.nlm.nih.gov/11565885/},
  note = {Source identifier: 11565885}
}