Chain Sudoku/en
Aus Puzzlewiki
Instructions
Fill the circles with digits 1 to n so that each digit occurs exactly once in every row, column and n-circle groups that are connected with lines.
History
This puzzletype was invented by Grabarchuk family in 2008, under the name Strimko. Later Conceptis launched same puzzle with the name "Chain Sudoku". Visit Conceptis Forum for discussions on copyright issues.