@article{EJDE_2001__2001__a210,
     author = {Amdeberhan, Tewodros},
     title = {Two symmetry problems in potential theory},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2001},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2001__2001__a210/}
}