@article{10_21136_CMJ_1972_101128,
     author = {R\'ab, Milo\v{s}},
     title = {Second order differential equations with complex-valued coefficients},
     journal = {Czechoslovak Mathematical Journal},
     pages = {590--599},
     publisher = {mathdoc},
     volume = {22},
     number = {4},
     year = {1972},
     doi = {10.21136/CMJ.1972.101128},
     mrnumber = {0315212},
     zbl = {0252.34006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1972.101128/}
}