Heading down the rabbit hole…
Qwikiverse maps the references between stories: what Superman: Red Son nods to, and what nods back. How it works
It is believed that the cover art can or could be obtained from DC Comics.
Fair use
Nothing spotted here yet.
A line quoted, a cameo, a character named after something: if Superman: Red Son nods to another story, or another story nods to it, spot the first one.