To cite package ‘SASmixed’ in publications use:

  Littell R, Milliken G, Stroup W, Wolfinger R, Bates D, Maechler M,
  Bolker B, Walker S (2026). _SASmixed: Data Sets from "SAS System for
  Mixed Models"_. R package version 1.0-5,
  <https://github.com/annahuynhly/sasmixed>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {SASmixed: Data Sets from "SAS System for Mixed Models"},
    author = {Ramon Littell and George Milliken and Walter Stroup and Russell Wolfinger and Douglas Bates and Martin Maechler and Ben Bolker and Steve Walker},
    year = {2026},
    note = {R package version 1.0-5},
    url = {https://github.com/annahuynhly/sasmixed},
  }