“…Since W F,d (a) always lies in Q(e 2πi/p ), we see that its valuation must be an integer multiple of 1/(p−1). Bounds on the p-adic valuation of W F,d (a) have proved very helpful in determining the values of W F,d (a), as can be seen in [1,2,3,4,5,6,7,10,15,16,20,21,24,26,27,28,29,34,36,37,40,41]. The main tool in determining the p-adic valuation of these Weil sums is Stickelberger's Theorem on the valuation of Gauss sums, which allows for an exact determination of (2) V F,d = min a∈F val p (W F,d (a)) in terms of a combinatorial formula that is given in Lemma 2.9 below.…”