Ganzoni, Cornelia, Ketina Arslani, Otmar Pfister, Michael Freese, Werner Strobel, Christian Mueller, and Daniel Tobler. “Choir Singing Improves Respiratory Muscle Strength and Quality of Life in Patients With Structural Heart Disease – HeartChoir: A Randomised Clinical Trial”. Swiss Medical Weekly 150, no. 3738 (September 16, 2020): w20346. Accessed July 22, 2024. https://smw.ch/index.php/smw/article/view/2867.