Collins, Roger. "The Vaccaei, the Vaceti, and the rise of Vasconia." Studia Historica VI. Salamanca, 1988. Reprinted in Roger Collins, Law, Culture and Regionalism in Early Medieval Spain. Variorum, 1992. ISBN0-86078-308-1.
Collins, Roger (1990). The Basques. Oxford, UK: Basil Blackwell. ISBN0-631-17565-2.
