1. Bombieri, E., Friedlander, J. B., and Iwaniec, H., Primes in arithmetic progression to large moduli, III, Journ. of the American Math. Soc. 2 (1989), 215–224.
2. Davenport, H. and Halberstam, H., The values of a trigonometrical polynomial at well spaced points, Mathematika 13 (1966), 91–96; Corrigendum and addendum, Mathematika 14 (1967), 229–232.
3. Elliott, P.D.T.A., Probabilistic Number Theory, I: Mean Value Theorems., Grund, der math. Wiss. 239, Springer Verlag, New York, Heidelberg, Berlin, 1979.
4. ——, Arithmetic Functions and Integer Products, Grund, der math. Wiss. 272, Springer Verlag, New York, Berlin, Heidelberg, Tokyo, 1985.
5. ——, Additive arithmetic functions on arithmetic progressions, Proc. Lond. Math. Soc. 54 (1987), 15–37.