Even more interaction--this time used in combination with other procedures...and a lot more heavily than in the first book.

The vast majority of sudoku puzzles that are labeled hard, expert, challenger, are not really all that difficult. And in a surprising number of cases, they are downright easy. Part of the Absolutely Nasty Sudoku series, this book provides basic and intermediate puzzles and techniques.

Only diehards need apply These incredibly difficult sudoku are made to challenge even the most expert solver...and strain their brains to bursting. Each puzzle requires upper-level strategies that have been honed to perfection from regular practice. Designed by powerhouse sudoku creator Frank Longo, they'll have dedicated fans tearing their hair out-and loving every moment. This is a bind-up of books 2, 3, and 4 our four-part Absolutely Nasty sudoku series.

A super-sequel to Mensa(R) Sudoku--which will easily equal the popularity of the first, 145,000 copies sold and climbing! Written by Frank Longo, one of the best sudoku creators around, it offers 534 fantastic puzzles (all in the standard 9x9 format) that go from very simple to extremely hard. That means smart newcomers can get started solving immediately and hone their skills as they proceed logically through the book. By the end, they'll have become experts, ready for any sudoku that comes their way.

Here it comes: a revolution in sudoku solving! This is by far the most complete guide to cracking these addictive puzzles ever produced, with tricks even the experts won t know. While most books might have a few pages of introduction before proceeding straight to the sudokus, this one covers it all: hidden pairs, naked pairs, X-wings, jellyfish, squirmbag, bivalue and bilocation graphs, turbot fish, grid coloring, and chains. Every single one is here, and much more too, including the exclusive Gordonian logic methods (Gordonian rectangles and Gordonian polygons) that will turn even the hardest puzzles into a breeze. Of course, there are hundreds of sudoku for practice. A very special addition is a reprint of the very first sudoku ever published in 1979, from "Dell Pencil Puzzles and Word Games" magazine!"

Wordoku is a cool combination of sudoku and wordplay--and it's the hottest new craze among puzzle lovers. This massive collection, which follows on the success of the two earlier "Big Books," will provide solvers with hours of fun. It features an amazing 900 wordoku, with grids in a variety of sizes: smaller 8x8s, standard 9x9s, and extra-hard 10x10s. The rules are simple, and almost exactly like sudoku--except with letters in place of numbers. Because the levels range from easy to brainbusting, everyone will find puzzles that are just challenging enough. Plus, when players are finished filling in the grid, they get to uncover a hidden word to complete the puzzle!

There’s a common belief about the mental acuity of the aging brain: "If you don’t use it, you lose it.” Research published in the December 20, 2006 issue of the Journal of American Medicine confirms it: "If we challenge our minds...it does in fact improve memory and this improvement can be sustained.” That’s why AARP has teamed up with puzzle expert Frank Longo to present this collection of sudoku puzzles guaranteed to provide a solid workout for brain cells that have been around the block. The puzzles, ranging from easy to medium in difficulty, offer a healthy dose of fun along with all the benefits of mental fitness. Solvers will reap the rewards of exercising concentration, care, and logic.