Logic Masters Deutschland e.V.

The Rules:

1. Normal sudoku rules apply.
2. [Sandwich]:Normal sandwich rules apply. Clues outside the grid (which must be deduced) indicate the sum of the digits between the 1 and 9 in that row or column.
3. [Zipper Lines]: The lavender lines are zipper lines. Numbers an equal distance from the center of a zipper line sum to the same total. For odd-length lines, the total is the digit placed in the line's center. Numbers may repeat on lines if allowed by sudoku.

The Puzzle:

Try it on CTC's Sudokupad - Answer Check is enabled, but only if you don't write any actual digits around the board of the grid, pencil marks would be fine though.