Scale work

[didi100]

I am working on the Grand Polonaise which has many octaves and thirds and difficult runs. Which book or books of scales would better prepare me to tackle these passages?

[lelle]

Scales, exercises in double notes and octaves may help, but in themselves they are not guaranteed to solve your problems. Doing those in combination with learning how to be more supple and relaxed as you play is what's needed. That will be much more effective than just playing exercises unless you are already naturally completely free. I have reason to doubt that you are, since you find these parts difficult. For that, I'd recommend finding a good teacher.

You don't really need a book if you want to play scales though. You can just play some scales.