@misc{indiciaef6dbcf542b59,
  title = {Mathematical methods for analyzing leads.},
  author = {R A HELM},
  year = {1959},
  doi = {10.1016/0002-8703(59)90365-5},
  url = {https://pubmed.ncbi.nlm.nih.gov/13606056/},
  note = {Source identifier: 13606056}
}