A Naruto fan, I presume?

: Focused on the early Naruto Shippuden era, detailing the Akatsuki and the Sasuke vs. Itachi showdown. Jin no Sho (Book of Formation)

The Fourth Databook, in particular, is vital for understanding the origins of Chakra, the Sage of the Six Paths, and the complex lineage of the Otsutsuki clan. A Note on Finding PDFs Safely

To no Sho (Second Databook): Covers the Search for Tsunade arc through the Sasuke Recovery Mission.