Reference: Bickel and Nichols 2013

Bickel, Balthasar & Johanna Nichols. 2013. Obligatory Possessive Inflection. In Matthew S. Dryer and Martin Haspelmath (eds.), The World Atlas of Language Structures Online. Leipzig: Max Planck Institute for Evolutionary Anthropology.

https://wals.info/chapter/58

@incollection{bickelnichols2013wals,
  address   = {Leipzig},
  author    = {Balthasar Bickel and Johanna Nichols},
  booktitle = {The World Atlas of Language Structures Online},
  editor    = {Matthew S. Dryer and Martin Haspelmath},
  publisher = {Max Planck Institute for Evolutionary Anthropology},
  title     = {Obligatory Possessive Inflection},
  url       = {https://wals.info/chapter/58},
  year      = {2013}
}