@article{MZ_1964__83_170217,
     author = {Ernst Wienholtz},
     title = {Zur {Regularit\"at} schwacher {L\"osungen} f\"ur elliptische {Systeme} partieller {Differentialoperatoren.}},
     journal = {Mathematische Zeitschrift},
     pages = {85--118},
     publisher = {mathdoc},
     volume = {83},
     year = {1964},
     zbl = {0156.34302},
     url = {http://geodesic.mathdoc.fr/item/MZ_1964__83_170217/}
}