Outpatient group therapy for post-COVID patients - a naturalistic feasibility study of a face-to-face and online group concept - Zimmermann-Schlegel, Verena; Gronewold, Nadine; Stengel, Sandra; Hartmann, Mechthild; Merle, Uta; Friederich, Hans-Christoph; Ditzen, Beate; Tesarz, Jonas (Frontiers in Psychiatry, 2024)