@article{10_14708_cm_v21i2_5999,
     author = {K. Zima},
     title = {A certain theorem on the oscillation of solutions of equation \((p(t)x')' + q(t)x = 0\)},
     journal = {Commentationes Mathematicae},
     pages = { 391--393},
     publisher = {mathdoc},
     volume = {21},
     number = {2},
     year = {1979},
     doi = {10.14708/cm.v21i2.5999},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v21i2.5999/}
}