1.
Sudoku Genius 144 of the Most Fiendish Puzzles Ever Devised
by Sheldon, Tom, Plume Books
ISBN: 9780452287501
List Price: $8.00
2.
Official Book of Sudoku 150 All-New Puzzles, Book 2
by Plume Books Staff
ISBN: 9780452287273
List Price: $10.00