APANTALLAMIENTO NUCLEAR MAGNETICO 3 CAMPOS MAGNETICOS NO UNIFORMES 3 GAUGE INVARIANCE 3 INVARIANCIA DE MEDIDA 3 MAGNETIC MULTIPOLES 3 MAGNETIC SUSCEPTIBILITY 3 MULTIPOLOS MAGNETICOS 3 NON UNIFORM MAGNETIC FIELD 3 NUCLEAR MAGNETIC SHIELDING 3 SUSCEPTIBILIDAD MAGNETICA 3 DENSIDAD DE CARGA ELECTRICA PERTURBADA A SEGUNDO ORDEN EN EL CAMPO MAGNETICO 2 ELECTRIC CHARGE DENSITY PERTURBED TO SECOND ORDER IN THE MAGNETIC FIELD 2 HIPERAPANTALLAMIENTO MAGNETICO NUCLEAR 2 HIPERSUSCEPTIBILIDAD MAGNETICA 2 MAGNETIC HYPERSUSCEPTIBILITY 2 NUCLEAR MAGNETIC HYPERSHIELDING 2