@article{KJM_2003_25_1_a8,
     author = {Julka Kne\v{z}evi\'c-Miljanovi\'c and Ljubica Lalovi\'c},
     title = {Investigation of stability on nonlinear oscilations with one degree of freedom},
     journal = {Kragujevac Journal of Mathematics},
     pages = {91 - 96},
     publisher = {mathdoc},
     volume = {25},
     number = {1},
     year = {2003},
     url = {http://geodesic.mathdoc.fr/item/KJM_2003_25_1_a8/}
}