Frank Longo

Love cryptograms? We’ve got lotsa them for the avid solver—600 puzzles that are funny, punny, and smart. For instance, can you figure out what this…

Build up your sudoku skills from easy to expert! In this three-book series, each book helps solvers build their skills to get from one level…

Build up your sudoku skills from easy to expert! In this three-book series, each book helps solvers build their skills to get from one level…

Build up your sudoku skills from easy to expert! In this three-book series, each book helps solvers build their skills to get from one level…

A collection of 105 easy to hard sudoku puzzles that will provide a perfect (and perfectly portable) break at any time of the day.

You say you can't get enough sudoku? Challenge accepted!With more than 900 puzzles at all difficulty levels (gradually increasing from easy to medium to hard), this massive collection should be…

Go way beyond difficult, with the hardest, most brain-busting sudoku you’ve ever seen!   Calling all sudoku-solving diehards: with every puzzle requiring upper-level strategies, this…

Sudoku super-master Frank Longo and mental_floss, the magazine for trivia lovers, bring fans a collection of superb puzzles sure to stimulate the brain. Longos puzzles…

Sudoku designers the world over will weep and gnash their teeth at the revelations in this comprehensive guide to cracking the addictive puzzles--but solvers will…

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…

Are you a sudoku warrior? Now you have an incredible opportunity to reach elite status and bask in the glory of completing some of the hardest…

Lounging by the pool is a great way to spend some leisure time, and great sudoku puzzles make it even better. Whether theyre on a…

For confident players only!

Watch out—these sudoku might crush even the most stalwart of solvers!

The fun begins with subsets and interaction.

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

The difficulty level soars, as even more tricks get added to the mix: X-Wing; Swordfish; XY-Wing; XYZ-Wing; and the Gordonian Rectangle.

Top solvers can try their hand at the One-Sided Gordonian Rectangle; Extended Gordonian Rectangle; Gordonian Polygon; and Alternating Digits. (But they can take comfort in…

Everyone loves sudoku puzzles, finding them impossible to put down. The only problem: having enough sudokus to solve!    Created in the United States, these…