Everybody likes fairies

If this doesn't belong here, tell me, and I'll get rid of it.

I've been trying for months to get a little more information on a particular Irish fairy. They're either called Dubh Sidhe or Fiach Dubh; all the information I get is that they're often called 'the Black faeries' or just 'Ravens', although putting either of those in a search engine lands me in late nineties goth websites. Using the Gaelic names gets me tons of information, but none of it in English. Does anyone knows another name they're known by? Or a few books that might be relevant to my interests?