  We improve the upper bounds of the following inequalities proved in [H. Alzer
and N. Batir, Monotonicity properties of the gamma function, Appl. Math.
Letters, 20(2007), 778-781]. \begin{equation*}
exp\left(-\frac{1}{2}\psi\left(x+\frac{1}{3}\right)\right)<\frac{\Gamma(x)}{\sqrt{2\pi}x^xe^{-x}}<exp\left(-\frac{1}{2}\psi(x)\right),
\end{equation*} and $$ \frac{1}{2}\psi'(x+1/3))<\log
x-\psi(x)<\frac{1}{2}\psi'(x).$$ Here $\Gamma$ is the classical gamma function
and $\psi$ is the digamma function.
