One could learn all there is to know of the techniques of war by reading this weighty tome.
A book made for battle.
Battle Folio is the weakest book, providing 7 Attack and 15 Weapon Defense. It can be bought for 3,000 gil at an Outfitter after meeting with Alphonse Delacroix at Lionel Castle in chapter 2 or by found as rare treasure at Clockwork City of Goug.
TA2 Battle Folio is the weakest book, providing 24 Attack, 5 Resistance, and 5 Magic. It teaches the abilities Study for 150 AP to the Scholar and Cura for 200 AP to the Seer. It can be obtained from the Bazaar from the "Moldy Tomes E" category.