My overview of Celtic initial consonant mutations appeared in The Wiley Blackwell Companion to Morphology, edited by Peter Ackema, Sabrina Bendjaballah, Eulàlia Bonet, and Antonio Fábregas.
I’m Pavel Iosad, and I’m a Professor in the department of Linguistics and English Language at the University of Edinburgh. ¶ You can always go to the start page to learn more.