@article{702332,
     title = {On the solvability of the non-homogeneous potential problem at a corner singularity},
     booktitle = {Equadiff 7},
     series = {GDML\_Books},
     publisher = {BSB B.G. Teubner Verlagsgesellschaft},
     address = {Leipzig},
     year = {1990},
     pages = {214-217},
     url = {http://dml.mathdoc.fr/item/702332}
}

Arscott, F. On the solvability of the non-homogeneous potential problem at a corner singularity, dans Equadiff 7, GDML_Books,  (1990), pp. 214-217. http://gdmltest.u-ga.fr/item/702332/