Post COVID-19 condition and its physical, mental and social implications: protocol of a 2-year longitudinal cohort study in the Belgian adult population., Smith, Pierre, Proesmans Kristiaan, Van Cauteren Dieter, Demarest Stefaan, Drieskens Sabine, De Pauw Robby, Cornelissen Laura, De Ridder Karin, and Charafeddine Rana , Arch Public Health, 2022 Jun 04, Volume 80, Issue 1, (2022)