Kermit Rose 
Second Book of Abc Puzzles [EPUB ebook] 

Do you like easy puzzles or hard puzzles? The difficulty of each puzzle in this book is your choice. To make the puzzle more difficult, choose fewer clues. To make the puzzle less difficult choose more clues. If you are good in Sudoku, then you will be able to work these puzzles with fewer clues. It is your choice how many clues you use. To make the solving a particular puzzle as easy as possible, you can examine all 84 clues. If you want more of a challenge, then minimize the clues you examine.