@article{MZ_1993__214_1_174594,
     author = {Giovanni Gregori},
     title = {On a general class of elliptic equations in devergence.},
     journal = {Mathematische Zeitschrift},
     pages = {683--695},
     year = {1993},
     volume = {214},
     number = {1},
     zbl = {0790.35030},
     url = {http://geodesic.mathdoc.fr/item/MZ_1993__214_1_174594/}
}