2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53427We compare results from $δ$--expansion, in simple theories, with self--consistent calculations as well as calculations involving the principle of minimal sensitivity. We show that the latter methods give relatively more accurate results order by order.8 pages, UR-1289High Energy Physics - TheoryHigh Energy Physics - Phenomenologytext