@article{oai:ir.jikei.ac.jp:00002942,
 author = {Koji, Kawahito and Hirokuni, Naganuma and Ken, Nakamura and Norimasa, Hajima},
 issue = {4},
 journal = {Jikeikai medical journal},
 month = {Dec},
 pages = {117--120},
 title = {Re-do Replacement Surgery for Degenerated Stentless Bioprostheses: The Open “Valve-in -Valve” Technique (Case Reports)},
 volume = {58},
 year = {2011}
}