Frank Longo
Frank Longo is an American puzzle creator and author known for publishing more than 90 books that have sold over 2 million copies. He is recognized for inventive crossword and word puzzles, including a 50x50 crossword and the New York Times Spelling Bee anagram puzzle.
puzzles
crossword puzzles
word games
The Nastiest Sudoku Book Ever
Sinister Sudoku: More Than 1,000 Fiendishly Tough Puzzles
Sit & Solve® Double Black Diamond Hard Sudoku (Sit & Solve® Series)
Challenging Thursday Sudoku (Sudoku (Sterling Publishing))
The Peaceful Mind Book of Sudoku (Peaceful Mind Puzzles)
Ninja Assassin Sudoku: Black Belt
CosmoGIRL! Games: Sudoku
Cranium-Crushing Friday Sudoku