@article{MZ_1967__101_170830,
     author = {Robert L. Borrelli},
     title = {The {...-Fredholm} {Property} for {Oblique} {Derivative} {Problems.}},
     journal = {Mathematische Zeitschrift},
     pages = {103--122},
     publisher = {mathdoc},
     volume = {101},
     year = {1967},
     zbl = {0148.35501},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__101_170830/}
}