Bednarczuk (Leszek): A typological contribution to the disappearance of p in Common Celtic.
In ZCP 49–50 (1997), pp. 43–49.
Examines the plausibility of an asymetrical phonological inventory where /b/ has no voiceless counterpart. Furthermore, argues that the loss of /p/ is not related to the lenition of voiceless stops as this phaenomenon postdates the Proto-Celtic period.