@article{JRAM_1917__147_149459,
     author = {Adolf Kneser},
     title = {Transformationsgruppen und {Variationsrechnung.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {54--66},
     year = {1917},
     volume = {147},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1917__147_149459/}
}