Olfactory training is helpful in postinfectious olfactory loss: a randomized, controlled, multicenter study. - Damm M; Pikart LK; Reimann H; Burkert S; Göktas Ö; Haxel B; Frey S; Charalampakis I; Beule A; Renner B; Hummel T; Hüttenbrink KB (The Laryngoscope, 2014)