@article{JRAM_1963__212_150574,
     author = {Woldemar Barthel},
     title = {Nichtlineare {Zusammenh\"ange} und deren {Holonomiegruppen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {120--149},
     publisher = {mathdoc},
     volume = {212},
     year = {1963},
     zbl = {0115.39704},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1963__212_150574/}
}