This Puzzle type appeared in the following championships
"18th World Puzzle Championship, Antalya (Turkey)"
World Sudoku Championship 2007
"Mini Kropki Sudoku" Instructions:
Place a digit from 1 to 6 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the six outlined 3x2 regions.
If absolute difference between two digits in neighboring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighboring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.