@misc{indiciaed39c60c37cbb,
  title = {On some isospectral second order differential operators.},
  author = {M Kac and P V Moerbeke},
  year = {1974},
  doi = {10.1073/pnas.71.6.2350},
  url = {https://pubmed.ncbi.nlm.nih.gov/16592161/},
  note = {Source identifier: 16592161}
}