David Dalby, 1999/2000, The Linguasphere register of the world’s languages and speech communities. Observatoire Linguistique, Linguasphere Press. Volume 2. Oxford.[1]Arkivigite je 2020-02-07 per la retarkivo Wayback Machine
David Dalby, 1999/2000, The Linguasphere register of the world’s languages and speech communities. Observatoire Linguistique, Linguasphere Press. Volume 2. Oxford.[1]Arkivigite je 2020-02-07 per la retarkivo Wayback Machine