@misc{indiciaeb4bdeeb236bd,
  title = {Mediastinal biopsy: the direct approach.},
  author = {J W Calvin and J E Connolly and E A Stemmer},
  year = {1967},
  url = {https://pubmed.ncbi.nlm.nih.gov/6016521/},
  note = {Source identifier: 6016521}
}