Beginner Clawhammer Player looking to play Irish music eventually

Hi folks, I've recently started playing at Irish sessions in 3 finger style, but I came across some of Ken Perlman's playing and really dug his approach.

I've only the rudiments of clawhammer playing, so could any of you good people recommend some instruction material which gives a good grounding in clawhammer playing, with a view to eventually playing Irish tunes in that style?

Thanks.