Looking for another SuDoku challenge? These 234 Quad (also known as Hyper) puzzles provide an extra source of puzzle-meant, in 5 difficulty levels-from Easy to Fiendish. Quad puzzles follow the same rules as for regular SuDoku puzzles PLUS there are 4 (Quad ) extra shaded regions where each region also contains the numbers 1 to 9 once only. Each Quad puzzle is joined to a previous and following puzzle through common puzzle solution numbers. As well, this book is an extension of "The World's Longest SuDoku Puzzle." Includes strategy guide for solving SuDoku puzzles, and tips on how to find Quad numbers. And for those who still can't get enough, try solving the 234 riddles Joe Defries is a current 2-time Guinness (TM) World Record Holder, and is the joe in suJoku.com & joe-ks.com (the Largest Source of Internet Humour). Look for more unique SuDoku puzzles in our upcoming 2fer Puzzle Series, including Music & Symbool SuDoku. You're well on your way to becoming a SuJokuholic