Ailie Munro's book was originally published as The Folk Music Revival in Scotland (Norwood Editions, 1985) and reissued, updated and expanded, as The Democratic Muse: Folk Music Revival in Scotland (Scottish Cultural Press, 1996). I haven't seen the second edition, but the first was very good.

Fred Woods' Folk Revival: The rediscovery of a national music (Blandford Press 1979), on the other hand, tends not to be very well thought of; it should be on any comprehensive reading list, but may need to be treated with caution.