@article{MZ_1976__147_172316,
     author = {Michael Wiegner},
     title = {Ein optimaler {Reularit\"atssatz} f\"ur schwache {L\"osungen} gewisser elliptischer {Systeme.}},
     journal = {Mathematische Zeitschrift},
     pages = {21--28},
     year = {1976},
     volume = {147},
     zbl = {0316.35039},
     url = {http://geodesic.mathdoc.fr/item/MZ_1976__147_172316/}
}