The observational clinical registry (cohort design) of the European Reference Network on Rare Adult Solid Cancers: The protocol for the rare head and neck cancers. - Trama, Annalisa; Licitra, Lisa; Cavalieri, Stefano; Bonfarnuzzo, Simone; Baili, Paolo; Ciarfella, Antonio; Parente, Pablo; Almadori, Giovanni; Ansarin, Mohssen; Bacigalupo, Almalina; Baumeister, Philipp; Baujat, Bertrand; et al. (PLoS ONE, 2023)