%0 Journal Article %A Christine Riedtmann %T Lie algebras and coverings. %J Commentarii mathematici Helvetici %D 1994 %P 291-310 %V 69 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMH_1994__69_4_140340/ %F CMH_1994__69_4_140340