%0 Journal Article %A Lewis, J. E. %T A Banach Space Whose Elements are Classes of Sets of Constant Width %J Canadian mathematical bulletin %D 1975 %P 679-689 %V 18 %N 5 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1975-119-6/ %R 10.4153/CMB-1975-119-6 %F 10_4153_CMB_1975_119_6