@article{JRAM_1902__124_149141,
     author = {E. Gr\"unfeld},
     title = {Beitr\"age zur {Theorie} der einer linearen {Differentialgleichung} nter {Ordnung} adjungirten {Differentialgleichungen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {134--142},
     publisher = {mathdoc},
     volume = {124},
     year = {1902},
     zbl = {32.0328.01},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1902__124_149141/}
}