Fiction books written like non-fiction

I'm not looking for fiction books that are written like memoirs (or biographies of fictional people) though… I think those are rather easy to come by. An exception would be if it actually is based around a real person, but -again- it should not feel like reading fiction.
As a side-note, I'm also not looking for books that were fraudulently published as non-fiction like "The Education of Little Tree" or "Misha: A Mémoire of the Holocaust Years" for example.

Also, not really looking for fictional reference guides, but if you know some fun ones you can still recommend them ("The Zombie Survival Guide" comes to mind). In general, I want it to follow a narrative though.

Plus point, if the book makes references to documents (they can be real or fictional) about the occurences/characters/etc. or/and has footnotes.
It should feel like the author researched a lot about the story before writing.

Examples I can think of:
The Name of the Rose by Umberto Eco (at least the beginning/introduction to the book)
The Royal Physician's Visit by Per Olov Enquist
A Ghost's Story by Lorna Gibb

Despite all my examples being historical fiction, I'm open to any genre (I don't typically like romance, though…)… can also be fantasy (more leaning towards urban fantasy or magical realism, though), horror, sci-fi, etc.

Thanks to everyone in advance 🙂