Elementary Proof of an Estimate for Kloosterman Sums with Primes

A new elementary proof of an estimate for incomplete Kloosterman sums modulo a prime q is obtained. Along with Bourgain’s 2005 estimate of the double Kloosterman sum of a special form, it leads to an elementary derivation of an estimate for Kloosterman sums with primes for the case in which the length of the sum is of order q^0.5+ε, where ε is an arbitrarily small fixed number.