A prospective study of salivary function sparing in patients with head and neck cancers receiving intensity-modulated or three-dimensional radiation therapy: Initial results. - Chao,K.S.; Deasy,J.O.; Markman,J.; Haynie,J.; Perez,C.A.; Purdy,J.A.; Low,D.A. (Int J Radiat Oncol Biol Phys, 2001)