Maddieson, Ian. 2008. Glottalized Consonants.
In: Haspelmath, Martin & Dryer, Matthew S. & Gil, David & Comrie, Bernard (eds.)
The World Atlas of Language Structures Online.
Munich: Max Planck Digital Library, chapter 7.
Available online at https://wals.info/feature/7
Accessed on 2008-03-28.
