@article{MS2_1967__21_166001,
     author = {Kjell-Ove Widman},
     title = {Inequalities for the {Green} {Function} and {Boundary} {Continuity} of the {Gradient} of {Solutions} of {Elliptic} {Differential} {Equations.}},
     journal = {Mathematica Scandinavica},
     pages = {17--37},
     year = {1967},
     volume = {21},
     zbl = {0164.13101},
     url = {http://geodesic.mathdoc.fr/item/MS2_1967__21_166001/}
}