This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Sudokuscanandcount.svg This Sudoku graph is modificated from the Crosshatching svg Crosshatching svg UTC Crosshatching svg Tim Stellmach derivative work sudokuscanandcount svg Crosshatching svg en Content only free positiononly free numberInhaltserklrung einzige freie Positioneinzige verbliebene Zahl ist sie ist fr dieses Feld