@article{JRAM_1896__116_148987,
     author = {Lothar Heffter},
     title = {Ueber gemeinsame {Vielfache} linearer {Differentialausdr\"ucke} und lineare {Differentialgleichungen} derselben {Klasse.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {157--166},
     publisher = {mathdoc},
     volume = {116},
     year = {1896},
     zbl = {27.0244.01},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1896__116_148987/}
}