A direct theorem for strictly convex domains in $\mathbb C^n$

For a strictly convex $C^2$-domain $\Omega\subset\mathbb C^n$ and a function $f\in\Lambda^a(\Omega)$ holomorphic in $\Omega$, we construct polynomials $P_n$, $\deg P_n\le N$, such that $|f(z)-P_n(z)|\le CN^{-a}$, $z\in\overline\Omega$. Bibliography: 12 titles.