Siironen, Päivi, et al. “Lymph Node Metastases and Elevated Postoperative Calcitonin: Predictors of Poor Survival in Medullary Thyroid Carcinoma”. Acta Oncologica, vol. 55, no. 3, Mar. 2016, pp. 357-64, doi:10.3109/0284186X.2015.1070963.