@article{MOMA_1977__83_177809,
     author = {K. Umgeher},
     title = {Das {Existenzproblem} multivalenter {L\"osungen} bei {Differentialgleichungen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {159--162},
     publisher = {mathdoc},
     volume = {83},
     year = {1977},
     zbl = {0358.34006},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1977__83_177809/}
}