@article{MZ_1960__74_169884,
     author = {Hans Wittich},
     title = {Eindeutige {L\"osungen} der {Differentialgleichung} w' = {R} (z, w).},
     journal = {Mathematische Zeitschrift},
     pages = {278--288},
     year = {1960},
     volume = {74},
     zbl = {0091.26102},
     url = {http://geodesic.mathdoc.fr/item/MZ_1960__74_169884/}
}