See e.g. https://da.wikipedia.org/wiki/Christian_Christensen_(forfatter) on https://bookbrainz.org/revision/149938 (beta too)

Parentheses are tricky though, because you’d want to capture "source: https://da.wikipedia.org/wiki/Christian_Christensen_(forfatter)" but not the final closing parenthesis of "(source: https://da.wikipedia.org/wiki/Christian_Christensen_(forfatter))" or either of the parentheses of "(https://bookbrainz.org/)", which might require some regex matching of parentheses to make sure the URL only includes as many ")" as it has "("… though I’m sure there are URLs with "))))))))" and such too, but not sure there’s a better way to handle that until we get BB-500.

Or we could do like Jira and include opening parentheses but not closing ones. 🙃 (Let’s not.)