%0 Journal Article %A Edward S. O'Keefe %T Verification of a Conjecture of Th. Skolem. %J Mathematica Scandinavica %D 1961 %P 80-82 %V 9 %I mathdoc %U http://geodesic.mathdoc.fr/item/MS2_1961__9_165764/ %F MS2_1961__9_165764