@article{JRAM_1979__0311_0312_152186,
     author = {H. Hueber},
     title = {On boundary {Harnack} principles and poles of extremal harmonic functions.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {384--388},
     publisher = {mathdoc},
     volume = {0311_0312},
     year = {1979},
     zbl = {0409.31009},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1979__0311_0312_152186/}
}