Some notes on Gorenstein projective modules

Let $R$ be a ring. It is proved that $(\mathcal{GP}(R), \mathcal{GP}(R)^\bot)$ is a complete hereditary cotorsion pair, where $\mathcal{GP}(R)$ denotes the class of the Gorenstein projective left $R$-modules. Then we get that each left $R$-module has a special Gorenstein projective precover. As an application, we prove that all Gorenstein projective left $R$-modules are Gorenstein flat over left noetherian rings.