To cite package ‘hashtable’ in publications use:

  Gu Z (2026). _hashtable: Hash Table and Hash Set_. R package version
  1.0.0, <https://CRAN.R-project.org/package=hashtable>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {hashtable: Hash Table and Hash Set},
    author = {Zuguang Gu},
    year = {2026},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=hashtable},
  }