Crystal, D. (1997). The Cambridge encyclopedia of language (2nd ed.). Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)Crystal, David. The Cambridge Encyclopedia of Language. 2nd ed. Cambridge ; New York: Cambridge University Press, 1997.
Lua MLA (8ú heag.)Crystal, David. The Cambridge Encyclopedia of Language. 2nd ed. Cambridge University Press, 1997.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.