Media type: E-Article Title: Two Cases of Quadricuspid Aortic Valve: Aortic Regurgitation and Degeneration Contributor: Jan Michael Federspiel; Thomas Tschernig; Matthias Werner Laschke; Hans-Joachim Schäfers imprint: 2022 Published in: The Thoracic & Cardiovascular Surgeon Reports Language: English DOI: 10.1055/s-0042-1750408 ISSN: 2194-7635; 2194-7643 Origination: Footnote: Access State: Open Access