@article{JRAM_1888__103_148729,
     author = {A. Hamburger},
     title = {Ueber eine specielle {Klasse} linearer {Differentialgleichungen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {238--273},
     year = {1888},
     volume = {103},
     zbl = {20.0320.02},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1888__103_148729/}
}