The main purpose of this paper is using the properties of Gauss sums and the estimate for character sums to study the hybrid mean value problem involving the two-term exponential sums and two-term character sums and give an interesting asymptotic formula for it.
"A Hybrid Mean Value Involving the Two-Term Exponential Sums and Two-Term Character Sums." J. Appl. Math. 2014 1 - 5, 2014. https://doi.org/10.1155/2014/845845