@article{ARM_1970__6_2_a0,
     author = {R\'ab, Milo\v{s}},
     title = {On the existence of solutions of certain nonlinear equations occurring in the transformation theory of a linear second order differential equation with complex valued coefficients},
     journal = {Archivum mathematicum},
     pages = {75--78},
     publisher = {mathdoc},
     volume = {06},
     number = {2},
     year = {1970},
     mrnumber = {0291532},
     zbl = {0236.34003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1970__6_2_a0/}
}