Green, David W.; Wei, Li (Nov 2016). “Code-switching and language control”. Bilingualism: Language and Cognition19 (5): 883–884. doi:10.1017/S1366728916000018.
“Welsh (adj.)”. Online Etymology Dictionary. 18 November 2019閲覧。 “As a noun, "the Britons," also "the Welsh language," both from Old English. The word survives in Wales, Cornwall, Walloon, walnut, and in surnames Walsh and Wallace.”
“Wales and Patagonia”. Wales.com - The official gateway to Wales. Welsh Government. 2016年5月22日閲覧。 “Today the province of Chubut, where most Welsh immigrants settled, has a population of 550,000 people. Of these, some 50,000 can claim Welsh ancestry and 5,000 speak the Welsh language.”