@article{JRAM_1930__162_149722,
     author = {E. Kamke},
     title = {Zur {Theorie} der linearen partiellen {Differentialgleichung} erster {Ordnung.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {185--197},
     publisher = {mathdoc},
     volume = {162},
     year = {1930},
     zbl = {56.0406.07},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1930__162_149722/}
}