Respiratory biofeedback and psycho-education for patients with post COVID- 19 symptoms and bodily distress: study protocol of the randomized, controlled explorative intervention trial POSITIV. - Dinse, Hannah; Skoda, Eva-Maria; Schweda, Adam; Jansen, Christoph; Schmidt, Kira; Konik, Margarethe; Rohn, Hana; Witzke, Oliver; Stettner, Mark; Kleinschnitz, Christoph; Bäuerle, Alexander; Teufel, Martin (Trials, 2025)