Reference: Hammarström et al. 2021

Hammarström, Harald, Robert Forkel, Martin Haspelmath & Sebastian Bank. 2021. Glottolog 4.4.

https://glottolog.org/ accessed 2021-10-05

@book{glottolog,
  address      = {Leipzig},
  author       = {Harald Hammarström and Robert Forkel and Martin Haspelmath and Sebastian Bank},
  howpublished = {Max Planck Institute for Evolutionary Anthropology},
  title        = {Glottolog 4.4},
  url          = {https://glottolog.org/ accessed 2021-10-05},
  year         = {2021}
}