Jackson, Kenneth Hurlstone. 1956. Language and History in Early Britain: a chronological survey of the Brittonic languages 1st to 12th century. Edinburgh: University Press.
@book{jacquesestimative-jackson56early, author = {Jackson, Kenneth Hurlstone}, publisher = {Edinburgh: University Press}, title = {Language and History in Early Britain: a chronological survey of the Brittonic languages 1st to 12th century}, year = {1956} }