Conrado O. Benitez, Philippine Progress Prior to 1898
“ Ilocanos.—A Malay people, with language of their own. At the discovery they had their peculiar culture and an alphabet. They inhabit the provinces of Ilocos Norte, Ilocos Sur, Union, and form the civic population of Abra, whose Tinguian peasants they Ilocanise. Since they are fond of wandering, their settlements are scattered in other provinces of Luzon, as Benguet, Pampanga, Cagayan, Isabela de Luzon, Pangasinan, Zambales, and Nueva Ecija. They are to be found as far as the east coast of Luzon. They are Christians and civilized. ”
