1. Rodrigues, Aryon Dall’Igna (1993). “Línguas Indígenas: 500 anos de descobertas e perdas”. Ciência Hoje 16/No 95: pp.20-26.
2. UNESCO Ad hoc Expert Group on Endangered Languages, (Matthias Brenzinger et al.) (2002). Language Vitality and Endangerment. online: http://www.unesco.org/culture/ich/doc/src/00120-EN.pdf
3. Wikipedia: http://en.wikipedia.org/wiki/Endangered_language
