European position paper on rhinosinusitis and nasal polyps 2020 - Fokkens, W.J.; Lund, V. J.; Hopkins, C.; Hellings, P. W.; Kern, R.; Reitsma, S.; Toppila-Salmi, S.; Bernal-Sprekelsen, M.; Mullol, J.; Anselmo-Lima, Wilma Terezinha (Rhinology Journal, 2020)