[ghaff]

There are tons of examples of course, but one that jumps to mind is Oath of Fealty by Jerry Pournelle where one of the plot points is an implant that gives the chosen few access to an encyclopedic database. Of course, today, a smartphone with cell access provides that (or at least a more chaotic version of same) to more or less everyone. You could also reasonably argue that the encyclopedia in Asimov's Foundation trilogy makes somewhat similar assumptions.

I do think some sort of AR interface is somewhere in the future but it's almost certainly a long way off for mainstream adoption.

[PopAlongKid]

>Oath of Fealty by Jerry Pournelle

and Larry Niven!

[ghaff]

Forgot Larry Niven was a co-author of that one. They tended to be a good pair on novel-length works. Niven's novels tended to end up as travelogues and Pournelle's ended up as military SF.