Heading down the rabbit hole…
Qwikiverse maps the references between stories: what Batman: Hush nods to, and what nods back. How it works
Wikipedia: Batman 608 (2002).jpg
https://www.dcuniverseinfinite.com/comics/book/batman-2010-608/61af5ab3-244d-4560-a50b-f7ff0d82bb8d/c
Fair use
Nothing spotted here yet.
A line quoted, a cameo, a character named after something: if Batman: Hush nods to another story, or another story nods to it, spot the first one.