discussion: Limitations to the equidistribution of primes (Friedlander and Granville, 1989).

the source to Montgomery is

Topics in multiplicative number theory (Springer, 1971)

Proc. Symp. Pure Math. 28, 307 (1976)

discussion: Limitations to the equidistribution of primes (Friedlander and Granville, 1989) and Small gaps between prime numbers (Soundararajan, 2007) (page 16).

the sources to Montgomery are

Topics in multiplicative number theory (Springer, 1971)

Proc. Symp. Pure Math. 28, 307 (1976)