[kstrauser]

That link’s a 404.

[gus_massa]

The link says

https://tug.org/TUGboat/tb08-1/tb17knutmix.pdf ¹

There is no space between pdf and ¹, so the HN server assumes incorrectly that the ¹ is part of the link.

[mschuster91]

Strip the superscript-1 character at the end, I'm surprised HNs link formatter regex detects it as part of the link: https://tug.org/TUGboat/tb08-1/tb17knutmix.pdf