@article{JRAM_1986__369_152847,
     author = {Gary M. Lieberman},
     title = {Regularity of solutions of nonlinear elliptic boundary value problems.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--13},
     year = {1986},
     volume = {369},
     zbl = {0585.35014},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1986__369_152847/}
}