%0 Journal Article %A A. A. Ilyin %T A~class of sharp inequalities for periodic functions. Addendum to the paper ``Smooth solutions of the Navier-Stokes equations'' by S.\,I.~Pokhozhaev %J Sbornik. Mathematics %D 2014 %P 220-223 %V 205 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_2014_205_2_a2/ %G en %F SM_2014_205_2_a2