Ferreira PR, Fleck JF, Diehl A, Barletta D, Braga-Filho A, Barletta A, Ilha L. Protective effect of alpha-tocopherol in head and neck cancer radiation-induced mucositis: a double-blind randomized trial. Head Neck. 2004 Apr;26(4):313–21. doi: 10.1002/hed.10382. PMID: 15054734.