О классах Никольского — Бесова на компактных симметрических пространствах ранга 1

Let $M$ be a compact symmetric space of rank 1. We have defined the Nikolskii— Besov type function classes $B^{r}_{p,\theta}(M)$ and we have obtained a conctructive description of this classes in in terms of the best approximation by the spherical polynomials on $M$.