@misc{indiciaec667474c81c6,
  title = {[Direct-vision heart surgery].},
  author = {R ZENKER and G HEBERER and H G BORST and H GEHL and W KLINNER and R BEER and M SCHMIDT-MENDE},
  year = {1959},
  doi = {10.1055/s-0028-1113653},
  url = {https://pubmed.ncbi.nlm.nih.gov/13639706/},
  note = {Source identifier: 13639706}
}