2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177887A brief summary of the status of neutrino masses, mixing and oscillations is presented. Neutrinoless double $β$-decay is considered. Predictions for the effective Majorana mass are reviewed. A possible test of the calculations of nuclear matrix elements of the $0νββ$-decay is proposed.A report at the International conference ``Non-Accelerator New Physics'' NANP05 Dubna, Russia, June 20-25, 2005High Energy Physics - Phenomenologytext