This puzzle has appeared in many World Puzzle Championships as well as World Sudoku Championships. As far as I can remember, I have seen this puzzle appearing in the 18th World Puzzle Championship, Antalya (Turkey), and World Sudoku Championship 2007.
At that time this puzzle was also known by the name as Dots Sudoku as in this Sudoku most of the time, not even a single digit will be given as hints.  It will be all Dots.
Now, Kropki Sudoku is appearing in World Sudoku Championship 2014. I am re-publishing this Sudoku as standard name Kropki Sudoku as 3rd Sudoku in
Rules of Kropki Sudoku
Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
If the absolute difference between two digits in neighboring cells equals 1, then they are separated by a white dot. If the digit is half of the digit in the neighboring cell, then they are separated by a black dot. The dot between 1 and 2 can be either white or black.
 Kropki Sudoku (Fun With Sudoku #3)
Kropki Sudoku (Fun With Sudoku #3) Solution

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