Rationale and design of an independent randomised controlled trial evaluating the effectiveness of aripiprazole or haloperidol in combination with clozapine for treatment-resistant schizophrenia - Piantato Ennio; Percudani Mauro; Pecchioli Stefania; Pacilli Anna; Occhionero Guglielmo; Nicholau Stylianos; Nosè Flavio; Mulè Serena; Moretti Daniele; Mollica Marco; Migliorini Giuseppe; Menchetti Marco; et al. (Trials, 2009)