David Nash Ford, "Early British Kingdoms" - "Timeline of the Early British Kingdoms 410 AD-598 AD", 1998: vedi [1]Archiviato il 21 agosto 2007 in Internet Archive..
Stevenson, Edward Luther. Trans. and ed. 1932. Claudius Ptolemy: The Geography. New York Public Library. Reprint: Dover, 1991, Latinized English translation, Book II Chapter 2, in linea a questo indirizzo da LacusCurtius.
David Nash Ford, "Early British Kingdoms" - "Timeline of the Early British Kingdoms 410 AD-598 AD", 1998: vedi [1]Archiviato il 21 agosto 2007 in Internet Archive..