When you get Vol1 he tells you he's actually interested in the other volumes too. Volumes 2,3,4,and 5 all comes from the bugs in the southwest map. The 3rd volume requires you to kill those walking plant elves looking monsters at Path to Caballa Relics.
PS- Volume 1 stays in your invent afterwards..so you can just let your friend borrow the book and let them do the quest. For me, I dug up vol1 at the southeast corner of the southwest map.
Click/warm my eggs up/feed my Pokemons...or a puppy/kitten/bunny/hamster(or ALL OF THE ABOVE) dies!!