The following variants are representative of my sudoku creations:
1. Ratio Sudoku
in the March 2006 issue of
http://nrich.maths.org/public/viewer.php?obj_id=48272. Pole Star Sudoku
a difference sudoku variant in the September 2006 issue of
http://nrich.maths.org/public/viewer.php?obj_id=54333. Quadruple Clue Sudoku
in the September 2008 issue of
http://nrich.maths.org/public/viewer.php?obj_id=6225This variant was used in the 2007 Second World Sudoku Championship, the 2007 Italian National Sudoku Championship and the 2008 Czech National Sudoku Championship.
4. Twin Corresponding Sudoku
in the November 2006 issue of
http://nrich.maths.org/public/viewer.php?obj_id=5477This variant was used in the 2007 Second World Sudoku Championship and the 2008 Czech National Sudoku Championship.
Please note that the basic concept of the variant would remain the same whether it is given the name of "Corresponding Twin Sudoku", "Corresponding Sudoku Twins", "Sudoku Corresponding Twins or any other label.
5. Multiplication Equation Sudoku
in the August 2008 issue of
http://nrich.maths.org/public/viewer.php?obj_id=6224