To cite package ‘epitools’ in publications use:

  Aragon T (2020). _epitools: Epidemiology Tools_. R package version
  0.5-10.1, <https://CRAN.R-project.org/package=epitools>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {epitools: Epidemiology Tools},
    author = {Tomas J. Aragon},
    year = {2020},
    note = {R package version 0.5-10.1},
    url = {https://CRAN.R-project.org/package=epitools},
  }