@article{JRAM_1895__114_148950,
     author = {G. Mittag-Leffler},
     title = {Sur les invariants des \'equations diff\'erentielles lin\'eaires. {(Extrait} d'une lettre de {M.} {Mittag-Leffler} au r\'edacteur).},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {306--308},
     publisher = {mathdoc},
     volume = {114},
     year = {1895},
     zbl = {26.0353.02},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1895__114_148950/}
}