Encyclopaedias, damn I've forgotten that used to be a thing. I think I still have a few somewhere that were used maybe once or twice. Now that was something internet search engines really made obsolete almost overnight.

Come to think of it though, as long as civilization has existed, libraries have been a thing. Or well, monasteries or some kind of place that kept records and copied books. And before that you just asked the oldest person in your village/tribe and hoped they knew I guess. It's weird that access to knowledge has basically been unchanged for the past ~10k or so years until now.