The additional aids endorsed by (ISC)²
Official (ISC)² CISSP Study Guide (Wiley). - Hardcover, e-Book. Kindle eBook @ $7.76 Official (ISC)² CISSP Practice Tests (Wiley). - Hardcover, e-Book. Kindle eBook @ $8.0  CISSP for Dummies (Wiley). Paperback, Kindle. Kindle version @ $5.0  Official CISSP Study App. Android, iOS versions. Individually @ <$10