Selenium and the Course of Mild Graves’ Orbitopathy - Marcocci, C; Kahaly, G J; Krassas, G E; Bartalena, L; Prummel, M; Stahl, M; Altea, M A; Nardi, M; Pitz, S; Boboridis, K; Sivelli, P; von Arx, G; Mourits, M P; Baldeschi, L; Bencivelli, W; Wiersinga, W; European Group on Graves' Orbitopathy (N Engl J Med, 2011)