This is weird. When I wrote my answer in that thread, I tried to include a link to scholar.google.com and got a popup that "Google links are not allowed"... but I just tried composing a new answer in that thread, and this time it would have accepted the link without complaining. Does not seem to be reproducible. Sorry.
@StephanKolassa No problem. For that answer the Google Scholar link seems relevant. It has since been edited in. I will ask the SE team if there is any type of filter.