A study of Montgomeryshire place-names

edition; published in 2001

A study of Radnorshire place-names

edition; published in 1998

Dictionary of the Place-Names of Wales

book published in 2007

Enwau Lleoedd Ym Maldwyn

Place-names of Gwent

edition; published in 2005

Place-names of Gwent

book (work)