Fatigue in Post-COVID-19 Syndrome: Clinical Phenomenology, Comorbidities and Association With Initial Course of COVID-19 oleh Lara Diem MD, Livia Fregolente-Gomes MD, Jan D. Warncke MSc, Helly Hammer MD, Christoph Friedli MD, Nicole Kamber MD, Simon Jung MD, Sandra Bigi PD, Manuela Funke-Chambour MD, Andrew Chan MD, Claudio L. Bassetti MD, Anke Salmen PD, Robert Hoepner PD