Guidelines of the International Headache Society for Controlled Clinical Trials in Cluster Headache. - Schoenen, Jean; Snoer, Agneta Henriette; Brandt, Roemer B; Fronczek, Rolf; Wei, Diana Y; Chung, Chin-Sang; Diener, Hans-Christoph; Dodick, David W; Fontaine, Denys; Goadsby, Peter J; Matharu, Manjit Singh; May, Arne; et al. (Cephalalgia, 2022)