Just like karate, these puzzle collections are ranked by different-coloured belts. Beginners can start with the extremely easy White Belt (Level 1), and move from book to book as their skills improve. By the time they reach Black (Level 9), they're ready to take on super-tough sudokos.
- Limba : Engleza
- Data Publicarii : 18 May 2006
- Format : Paperback
- Numar pagini : 96
- ISBN : 9781402737541