Longitudinal Evaluation of an Integrated Post–COVID-19/Long COVID Management Program Consisting of Digital Interventions and Personal Support: Randomized Controlled Trial - Christina Derksen; Robin Rinn; Lingling Gao; Alina Dahmen; Cay Cordes; Carina Kolb; Petra Becker; Sonia Lippke (Journal of Medical Internet Research, 2023)