400 Easy Checkmates in One Move for Beginners, Part 4 (Chess Puzzles for Kids)
by Andon Rangelov
180 Checkmates Chess Puzzles in Two Moves, Part 2 (The Right Way to Learn Chess with Chess Lessons and Chess Exercises)
by Andon Rangelov
Unbelievably Hard Sudokus Collection for Sudoku Expert #5
by Masaki Hoshiko