Controversy: does repetitive transcranial magnetic stimulation/ transcranial direct current stimulation show efficacy in treating tinnitus patients? - Langguth, Berthold; Ridder, Dirk de; Dornhoffer, John L.; Eichhammer, Peter; Gonçalves, Márcia R.; Frank, Elmar; Fregni, Felipe; Gerloff, Christian; Khedr, Eman; Kleinjung, Tobias; Landgrebe, Michael; Lee, Scott; et al. (Brain Stimulation, 2008)