Heading down the rabbit hole…
Qwikiverse maps the references between stories: what Action Comics #1 (Superman debut) nods to, and what nods back. How it works
Wikipedia: Action Comics 1.jpg
"DC Comics Celebrates 'Action Comics' #1000 and 80 Years of Superman With Commemorative Book: Exclusive" at Newsweek. Retrieved . (similar file if not the one originally uploaded.)
Fair use
Nothing spotted here yet.
A line quoted, a cameo, a character named after something: if Action Comics #1 (Superman debut) nods to another story, or another story nods to it, spot the first one.