%0 Journal Article %A S. M. Voronin %T On differential independence of $\zeta$-functions %J Doklady Akademii Nauk %D 1973 %P 1264-1266 %V 209 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1973_209_6_a2/ %G ru %F DAN_1973_209_6_a2