%0 Journal Article %A V. N. Zhelyabin %A A. A. Popov %A I. P. Shestakov %T The coordinate ring of an $n$-dimensional sphere and some examples of differentially simple algebras %J Algebra i logika %D 2013 %P 416-434 %V 52 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/AL_2013_52_4_a1/ %G ru %F AL_2013_52_4_a1