Domino Sudoku

Recently I noticed in my website statistics some people coming from a Spanish weblog su.doku.es. Here I found another example of a Sudoku variant called Domino Sudoku. Although the text is in Spanish I don't think an explanation on how to solve this Domino Sudoku is necessary. Just combine the rules of Sudoku and Domino to solve this puzzle.

Tags: Sudoku | Domino