(Translated by https://www.hiragana.jp/)
Ethnic Groups of Europe: An Encyclopedia - Jeffrey Cole - Google-kirjat
The Wayback Machine - https://web.archive.org/web/20200811052712/https://books.google.com/books?id=Wlth0GRi0N0C&q=guage&source=gbs_word_cloud_r&cad=5