Location: Sky Island
In the far north east, is a big building with Ludwig in. This is part of the main questline, and you won't miss going here. You may miss the part of this building if you're not paying attention though.
Once inside, go to the north section of the building, and in there will be 3 books. Two are in the bookshelves, and the other will be on the table.
They are:
Memoirs
Archimedes: Grand Inventor
Chronological Events
Once in there, you won't really miss them as they have markers by them. But you may overlook that area if you're rushing. Hope this helps.