@article{AUPO_2012__51_2_a9,
     author = {Ukpera, Awar Simon and Adesina, Olufemi Adeyinka},
     title = {Results on {Non-resonant} {Oscillations} for some {Nonlinear} {Vector} {Fourth} {Order} {Differential} {Systems}},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {129--140},
     publisher = {mathdoc},
     volume = {51},
     number = {2},
     year = {2012},
     mrnumber = {3058878},
     zbl = {06204935},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_2012__51_2_a9/}
}