TITLE: Vinogradov-Korobov for Dirichlet L-functions?
QUESTION [6 upvotes]: Where can one find a Vinogradov-Korobov zero-free region for Dirichlet L-functions? It has to be in a standard reference, but I'm having a non-trivial time finding it.

REPLY [2 votes]: In Theorem 2 of Mark Coleman's paper below, a full proof of the Vinogradov-Korobov zero-free region for the $L$-function of a Grossencharacter twisted by a Hecke character over an arbitrary number field is provided.  Restricting to $K=\mathbb{Q}$, one recovers the result for Dirichlet $L$-functions.  This is the only place where I have seen a full proof of such a zero-free region published.
Coleman, M. D., A zero-free region for the Hecke L-function, Mathematika 37, No. 2, 287-304 (1990). ZBL0721.11050.