Screening Tests for Cushing’s Syndrome: Urinary Free Cortisol Role Measured by LC-MS/MS - Ceccato, F; Barbot, M; Zilio, M; Frigo, A C; Albiger, N; Camozzi, V; Antonelli, G; Plebani, M; Mantero, F; Boscaro, M; Scaroni, C (J Clin Endocrinol Metab, 2015)