@article{JRAM_1900__122_149091,
     author = {Alf Guldberg},
     title = {Zur {Theorie} der unbeschr\"ankt integrablen totalen {Differentialgleichungen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {34--42},
     publisher = {mathdoc},
     volume = {122},
     year = {1900},
     zbl = {31.0368.04},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1900__122_149091/}
}