@misc{indiciae9e142cee01b5,
  title = {[Direct vision open 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-0028-1113641},
  url = {https://pubmed.ncbi.nlm.nih.gov/13639694/},
  note = {Source identifier: 13639694}
}