%0 Journal Article %A Robert Deville %A %A %T Analytic and $C^k$ approximations of norms in separable Banach spaces %J Studia Mathematica %D 1996 %P 61-74 %V 120 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-120-1-61-74/ %R 10.4064/sm-120-1-61-74 %G en %F 10_4064_sm_120_1_61_74