Define
where
(Davenport 1980, p. 121), is the Mangoldt function, and is the totient function. Now define
where the sum is over relatively prime to , , and
Bombieri's theorem then says that for fixed ,
provided that .
More things to try:
Weisstein, Eric W. "Bombieri's Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/BombierisTheorem.html