Effectiveness and acceptability of the unified protocol for the transdiagnostic treatment of emotional disorders in people with long COVID-19: Study protocol for a randomized controlled trial - Verónica Martínez-Borba; Andrés E. Rodríguez-Márquez; Sara Garcés-Arilla; Óscar Peris-Baquero; María Vicenta Navarro-Haro; Esther del Corral-Beamonte; Jorge Osma (PLoS ONE, 2026)