ウェールズ英語
Coupland, Nikolas (1988), Dialect in Use: Sociolinguistic Variation in Cardiff English, University of Wales Press, ISBN 0-70830-958-5, https://books.google.com/books?id=W8kmAAAAMAAJ
English in Wales: Diversity, Conflict, and Change, Multilingual Matters Ltd., (1990), ISBN 978-1-85359-032-0, https://books.google.com/books?id=tPwYt3gVbu4C
Crystal, David (4 August 2003), The Cambridge Encyclopedia of the English Language Second Edition, Cambridge University Press, ISBN 9780521530330, https://books.