Will Shortz Presents the Ultimate Kenken Omnibus: 500 Easy to Hard Logic Puzzles That Make You SmarterPaperback, 13 October 2009

Perfect for solvers who just can't get enough, this colossal collection contains 500 easy to hard KenKen puzzles -- perfect for novices and experts alike.

Features:

• 500 easy-to-hard KenKen puzzles
• Edited by legendary New York Times crossword editor Will Shortz
• Big grids with lots of space for easy solving