Eberhard et al. (eds.) 2020

Eberhard, D. M. and Simons, G. F. and Fennig, C. D. (eds.) 2020. Ethnologue: Languages of the World (23rd ed.) Dallas, TX: SIL International.

http://www.ethnologue.com

@book{eberhard2020,
  address   = {Dallas, TX},
  editor    = {Eberhard, D. M. and Simons, G. F. and Fennig, C. D.},
  publisher = {SIL International},
  title     = {Ethnologue: Languages of the World (23rd ed.)},
  url       = {http://www.ethnologue.com},
  year      = {2020}
}