@article{AUPO_1991__30_1_a3,
     author = {Zeman, Ji\v{r}{\'\i}},
     title = {On some continuities of phases theory and {WKB} method for linear differential equation of the second order},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {39--47},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {1991},
     mrnumber = {1166424},
     zbl = {0752.34034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1991__30_1_a3/}
}