Sudoku Kropki - 200 Logic Puzzles 6x6 (Volume 1)

Kropki Sudoku (the Polish word "kropki" means "dots"; also known as "Dots Sudoku") is the variation of the original sudoku.
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.