^Hammarström, Harald; Forkel, Robert; Haspelmath, Martin; Bank, Sebastian (编). Mpi. Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History. 2016.
更多
Ladefoged, Peter; Maddieson, Ian. The Sounds of the World's Languages. Oxford: Blackwell. 1996. ISBN 0-631-19814-8 (英语).