Pre-War book (Fallout: New Vegas)

A pre-War book is a book that has not been destroyed. It is a fairly rare item, desired by the Capital Wasteland Brotherhood of Steel. Specifically, the Brotherhood Scribe Yearling, located within the Arlington Library, will reward you with 10 XP and 100 bottle caps per book for contributing these to their archives. See Yearning for Learning.

Locations
G.E.C.K. shows that there are 111 Pre-War Books ("BookGeneric01") in the game, more are added with add-ons. The links below often tell you where to find them: