↑ Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert và đồng nghiệp biên tập (2013). “Celtic”. Glottolog. Leipzig: Max Planck Institute for Evolutionary Anthropology. Gợi ý |số biên tập viên= (trợ giúp)
↑ The Celtic languages:an overview, Donald MacAulay, The Celtic Languages, ed. Donald MacAulay, (Cambridge University Press, 1992), 3.
↑ Cunliffe, Barry W. 2003. The Celts: a very short introduction. pg.48
↑ "Languages Spoken At Home" from Australian Government Office of Multicultural Interests website. Retrieved 27 December 2007; G. Leitner, Australia's Many Voices: Australian English--The National Language, 2004, pg. 74
