Ethnologue.

APA Citation

Summer Institute of Linguistics., Wycliffe Bible Translators. Ethnologue. Dallas, Tex. [etc.]: Summer Institute of Linguistics [etc.].

MLA Citation

Summer Institute of Linguistics, and Wycliffe Bible Translators. Ethnologue. Dallas, Tex. [etc.]: Summer Institute of Linguistics [etc.],

Warning: These citations may not always be complete (especially for serials).