@misc{indiciae6c2f74271ae3,
  title = {An improved mitral valve prosthesis.},
  author = {A C Beall and G C Morris and G P Noon and G A Guinn and G J Reul and E A Lefrak and S D Greenberg},
  year = {1973},
  doi = {10.1016/s0003-4975(10)64930-2},
  url = {https://pubmed.ncbi.nlm.nih.gov/4264465/},
  note = {Source identifier: 4264465}
}