http://www.denofgeek.com/us/books-comics/gotham/249408/gotham-season-2-dc-comics-and-batman-easter-egg-reference-guide

Welcome to Gotham Central! This is your one stop location for every Batman and DC Comics reference in Gotham season 2.

5 essential BATMAN comics for fans of GOTHAM (the series).

https://editorial.rottentomatoes.com/article/5-essential-dc-comics-for-the-gotham-fan