Jakobi, Annika, et al. “NTCP Reduction for Advanced Head and Neck Cancer Patients Using Proton Therapy for Complete or Sequential Boost Treatment Versus Photon Therapy”. Acta Oncologica, vol. 54, no. 9, Oct. 2015, pp. 1658-64, doi:10.3109/0284186X.2015.1071920.