@misc{indiciaed321a29550b6,
  title = {The electrocardiogram in chronic obstructive lung disease.},
  author = {J Ruskin and E H Estes and J C Greenfield},
  year = {1969},
  doi = {10.1097/00007611-196904000-00016},
  url = {https://pubmed.ncbi.nlm.nih.gov/5777529/},
  note = {Source identifier: 5777529}
}