To cite package ‘markdown’ in publications use:

  Xie Y, Allaire J, Horner J (2026). _markdown: A Thin Wrapper of
  'litedown' to Render Markdown Documents_. R package version 2.1,
  <https://CRAN.R-project.org/package=markdown>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {markdown: A Thin Wrapper of 'litedown' to Render Markdown Documents},
    author = {Yihui Xie and JJ Allaire and Jeffrey Horner},
    year = {2026},
    note = {R package version 2.1},
    url = {https://CRAN.R-project.org/package=markdown},
  }