9338.
Journal of Celtic linguistics 13 (Mar. 2009)
University of Wales Press
9342.
Zimmer (Stefan): The name of Arthur: a new etymology.
In JCeltL 13 (Mar. 2009), pp. 131–136.
Suggests it is from Celtic *Arto-rı̄g-i̯os, a derivative of *Arto-rı̄χs (= OIr. Artrí).