Bibliography
Bibliography of Vitality:
Robert J. Conrad and Ronald K. Lewis. 1988. "Some Language and Sociolinguistic Relationships in the Upper Sepik Region of Papua New Guinea." In Papers in New Guinea Linguistics 26, 76: 243-273. Canberra: Research School of Pacific and Asian Studies, Australian National University.
Bibliography of Locations:
Anthony Aristar, Helen Aristar-Dry and Yichun Xie. 2012. "LL-MAP (Language and Location: A Map Accessibility Project)." Online: http://llmap.org.
Bibliography of Context:
Lewis, M. Paul, Gary F. Simons, and Charles D. Fennig (eds.). 2015. Ethnologue: Languages of the World, Eighteenth edition. Dallas, Texas: SIL International. Online version: http://www.ethnologue.com.