To cite the ‘ouch’ package in publications, use:

  M. A. Butler and A. A. King (2004). Phylogenetic comparative
  analysis: a modeling approach for adaptive evolution. American
  Naturalist 164:683–695. DOI:10.1086/426002.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Aaron A. King and Marguerite A. Butler},
    title = {Phylogenetic comparative analysis: a modeling approach for adaptive evolution},
    journal = {American Naturalist},
    year = {2004},
    volume = {164},
    pages = {683--695},
    doi = {10.1086/426002},
  }

Additionally, consider citing the package itself:

  Aaron A. King and Marguerite A. Butler (2024). ouch:
  Ornstein-Uhlenbeck models for phylogenetic comparative hypotheses. (R
  package, version 2.20-0). https://kingaa.github.io/ouch/

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ouch: Ornstein-Uhlenbeck models for phylogenetic comparative hypotheses},
    author = {Aaron A. King and Marguerite A. Butler},
    year = {2024},
    note = {R~package, version~2.20-0},
    url = {https://kingaa.github.io/ouch/},
  }