135 books • 16 series
Level 7 Brown Belt Sudoku (Martial Arts Sudoku S.)
Level 6 Purple Belt Sudoku (Martial Arts Sudoku S.)
The Official Book of Wordoku
Second-Degree White Belt Sudoku®
Second-Degree Black Belt Sudoku®
Second-Degree Green Belt Sudoku®
Second-Degree Brown Belt Sudoku®
The World's Longest Crossword Puzzle
Point & Solve Crosswords
The Brainiac's Puzzle Book
Lord of the Rooms Musings and Observations of a Front Desk Clerk
Cranium Crushing Crosswords
The New York Times on the Web Crosswords for Teens (New York Times Crossword Puzzles)
Big Book of Wordoku Puzzles
Fertilization