@article{IM_1976__33_142376,
     author = {Giuseppe Chiti},
     title = {A {W} 2, 2  {Bound} for a {Class} of {Elliptic} {Equations} in {Nondivergence} {Form} with {Rough} {Coefficients.}},
     journal = {Inventiones mathematicae},
     pages = {55--60},
     publisher = {mathdoc},
     volume = {33},
     year = {1976},
     zbl = {0327.35023},
     url = {http://geodesic.mathdoc.fr/item/IM_1976__33_142376/}
}