TY - JOUR AU - Ukpera, Awar Simon AU - Adesina, Olufemi Adeyinka TI - Results on Non-resonant Oscillations for some Nonlinear Vector Fourth Order Differential Systems JO - Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica PY - 2012 SP - 129 EP - 140 VL - 51 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/AUPO_2012__51_2_a9/ LA - en ID - AUPO_2012__51_2_a9 ER -