1. Besha, R. 1993. A Classified Vocabulary of the Shambala
Language, with Outline Grammar. Tokyo: Institute for the Study of
Languages and Cultures of Asia and Africa.
2. Charters, D. 2015. The Teaching and Learning of Esperanto.
Interdisciplinary Description of Complex Systems 13.2,
288–298. 10.7906/indecs.13.2.7
3. Davies, J. 1981. Kobon.
Lingua Descriptive Studies 3. Amsterdam:
North-Holland.
4. Dryer, M. 2013. Chapter Indefinite Articles. In: M. Dryer & M.
Haspelmath (eds.), The World Atlas of Language Structures
Online. Leipzig: Max Planck Institute for Evolutionary
Anthropology.
5. Gary, J. & S. Gamal-Eldin. 1982. Cairene Egyptian Colloquial
Arabic. Lingua Descriptive Studies 6. London: Croom
Helm.