Protocol of a randomized, double-blind, placebo-controlled, parallel-group, multicentre study of the efficacy and safety of nicotinamide in patients with Friedreich ataxia (NICOFA) oleh Kathrin Reetz, Ralf-Dieter Hilgers, Susanne Isfort, Marc Dohmen, Claire Didszun, Kathrin Fedosov, Jennifer Kistermann, Caterina Mariotti, Alexandra Durr, Sylvia Boesch, Thomas Klopstock, Francisco Javier Rodríguez de Rivera Garrido, Ludger Schöls, Thomas Klockgether, Massimo Pandolfo, Rudolf Korinthenberg, Philip Lavin, Geert Molenberghs, Vincenzo Libri, Paola Giunti, Richard Festenstein, Jörg B. Schulz, the EFACTS or NICOFA study group