book jungle..

Since I am stuck in a square with my palying i have decide to buy one or maybe two books.

I need a book that can help me with my left/ rigth hand technique and a book where i can lern my thery, scals, mods etc.

What do you guys think about these books:

- Bass Fitnnes by Josquin des Pres for my technique

- Bass Scale Manual by Harvey Vinson for my theory