Randomized clinical trial “olfactory dysfunction after COVID-19: olfactory rehabilitation therapy vs. intervention treatment with Palmitoylethanolamide and Luteolin”: preliminary results - D'Ascanio, L; Vitelli, F; Cingolani, C; Maranzano, M; Brenner, M J; Di Stadio, A (Eur Rev Med Pharmacol Sci, 2021)