@misc{indiciaeb919ecc9b5d9,
  title = {Nonintegral Maslov indices.},
  author = {H Friedrich and J Trost},
  year = {1996},
  doi = {10.1103/physreva.54.1136},
  url = {https://pubmed.ncbi.nlm.nih.gov/9913582/},
  note = {Source identifier: 9913582}
}