%0 Journal Article %A Sirakov, Boyan %T Symmetry for exterior elliptic problems and two conjectures in potential theory %J Annales de l'I.H.P. Analyse non linéaire %D 2001 %P 135-156 %V 18 %N 2 %I Elsevier %U http://archive.numdam.org/item/AIHPC_2001__18_2_135_0/ %G en %F AIHPC_2001__18_2_135_0