2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189109I review some of the recent progress (up to December 2005) in applying non-Abelian discrete symmetries to the family structure of leptons, with particular emphasis on the tribimaximal mixing ansatz of Harrison, Perkins, and Scott.14 pages, no figure, talk at WHEPP-9High Energy Physics - Phenomenologytext