One is “The History of the Undying King†and the other is “The Elven Peoples of Icefiaâ€.
Robert doesn't know a ton of history, so unless those relate to the law or the Messada / Port Phiam area, I don't know anything but the obvious.
The books are thrown about, so is it safe to assume that whoever went through these was looking for those? Or could they just happen to have been on top? Are any of the books obviously valuable from a material standpoint? Gold laden, etc?