Letter from Fita to Fernández Guerra, reproduced in his Cantabria, note 8, page 126, reproduced in Historia crítica de Vizcaya y de sus Fueros, by fr:Gregorio Balparda, according to Auñamendi Entziklopedia
Letter from Fita to Fernández Guerra, reproduced in his Cantabria, note 8, page 126, reproduced in Historia crítica de Vizcaya y de sus Fueros, by fr:Gregorio Balparda, according to Auñamendi Entziklopedia