Questions regarding WSC round 5 - Arrows, Lines and Circles

[Richard]

Hi,

I noticed while looking at the IB that you used a palindrome sudoku which I've created. It is not a WPF sudoku. You'll find it on my blog with reference to the competition in which it appears initially.
Can you add my name in the credit section in the next version of IB?

Thanks,
Fred

We took this example from the Instruction Booklet of the Dutch Grand Prix Round in 2016 (and maybe it's used more often, I don't know; we started with our own rounds), so we believed it is a WPF-puzzle.