Title: Hard Sudoku Puzzles, Square Mazes, and More Activity Book: Fun Puzzles for the Mind, Author: Clem Burrows
Title: Sudoku Puzzles and Simple Mazes Variety Activity Book: With Mandela Style Coloring Pages, Word and Number Searches, Author: Royal Wisdom
Title: Simply Square Mazes: 86 Difficult Mazes Levels 1-5, Author: Clem Burrows
Title: Easy to Difficult Sudoku and Mazes Activity Book: Fun Activities to Challenge Your Brain and Sharpen Your Mind, Author: Clem Burrows