Easy Jigsaw Sudoku Puzzle Books: Irregular Sudoku Books for Adults (Adult Activity Book Games Puzzles and More Brain Workouts): Fun, Learn &: 9798791903587: Amazon.com: Books
Puzzle No. 278, 279 : An Irregular Sudoku and an Irregular Parquet | PS's puzzles +
Irregular Sudoku (Mini Sudoku Series #19)
Irregular Sudoku Puzzle (Fun With Sudoku #279)
PUZZLE 23. IRREGULAR SUDOKU | SOLVE THE UNSOLVABLE