with the algorithms I used for creating Sudokus in my Android app I decided to give Amazon Create Space a try, where you can publish books and let them print on demand.
So I created two books, one contains 100 Sudokus and the other 200, with 5 different difficulties and with the solutions.
The books are available on http://www.amazon.de/100-Sudokus-Leicht-Oliver-Scheel/dp/1522937277/ref=sr_1_1?s=books&ie=UTF8&qid=1452275426&sr=1-1&keywords=oliver+scheel+sudoku and http://www.amazon.de/200-Sudokus-Leicht-Oliver-Scheel/dp/1522961801/ref=sr_1_2?s=books&ie=UTF8&qid=1452275426&sr=1-2&keywords=oliver+scheel+sudoku, there you can also take a look in the book.
(sorry, so far it is only German, if someone is really interested - but there's not much text anyway except the difficulties).
So I would be very interested, do you think this is something useful, do you buy Sudokus books yourself and how do you find my books?
Thanks and have a good weekend!