Frank Longo has had more than 3,000 crossword puzzles published since 1993, and in the past few years has turned his attention to the sudoku craze. He has published over 90 sudoku books, including Oy Vey! Sudoku; 10x10 Sudoku; Mensa® Absolutely Nasty Sudoku Level 1, 2, 3, and 4; The World's Longest Sudoku Puzzle; The Sudoku Code (coauthored with Francis Heaney); and Mensa® Guide to Solving Sudoku (coauthored with Peter Gordon).