@article{JRAM_1941__183_183495,
     author = {Gerhard Kowalewski},
     title = {Zur nat\"urlichen {Geometrie} der irreduziblen {G6} von {Ber\"uhrungstransformationen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {243--250},
     year = {1941},
     volume = {183},
     zbl = {0025.22601},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1941__183_183495/}
}