Wikipedia tends to be pretty high-level, i.e. focus more on people, events, general principles, high-level summaries of how things are and their history. But in case of a societal collapse, wouldn't that be kinda useless? Not sure what specific pieces of literature you'd want to have on your emergency hand crank emp-shielded Kindle, but I'd expect more hands-on material would be preferable, i.e. material that tells you how to make and do certain practical things and the right technique and relevant caveats.