Screening for colorectal cancer with FOBT, virtual colonoscopy and optical colonoscopy: study protocol for a randomized controlled trial in the Florence district (SAVE study). - Sali, Lapo; Grazzini, Grazia; Carozzi, Francesca; Castiglione, Guido; Falchini, Massimo; Mallardi, Beatrice; Mantellini, Paola; Ventura, Leonardo; Regge, Daniele; Zappa, Marco; Mascalchi, Mario; Milani, Stefano (Trials, 2013)