TY - JOUR AU - Guzman, Adolfo W. TI - Structural stability of polynomial second order differential equations with periodic coefficients JO - Electronic Journal of Differential Equations PY - 2004 VL - 2004 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/EJDE_2004__2004__a69/ LA - en ID - EJDE_2004__2004__a69 ER -