Effects of Zinc Supplementation on Clinical Outcomes in Patients Receiving Radiotherapy for Head and Neck Cancers: A Double-Blinded Randomized Study - Lin, Li-Ching; Que, Jenny; Lin, Kuei-Li; Leung, Henry Wing-Cheung; Lu, Chin-Li; Chang, Ching-Hsiung (International Journal of Radiation Oncology, Biology, Physics, 2008)