複素多様体論 I,II,III
《複素多様体論 I,II,III》 · 第 11 页 · Section 2.3，Lemma 2.4
Weyl's inequality. Suppose that $(a,q)=1$, $|\alpha-a/q|\le q^{-2}$, $\phi(x)=\alpha x^k+\alpha_1x^{k-1}+\cdots+\alpha_k$, and $T(\phi)=\sum_{x=1}^{Q}e(\phi(x))$. Then $T(\phi)\ll Q^{1+\varepsilon}(q^{-1}+Q^{-1}+qQ^{-k})^{1/K}$, where $K=2^{k-1}$.