AIUI Project Gutenberg has a stable URI for each work, with an “ebook number” built in. And they keep old versions, when they fix errata, so URI and date should be enough to retrieve exactly what you read .

Maybe @gutenberg_org can refine this?

just from volunteering at Distributed Proofreaders I ran across enough edge cases inherited from the printed works to make a “Fallacies Programmers Believe About Books”.

@weirdfish @kallekn @gisiger @bookstodon