To cite package 'PACKAGENAME' in publications use:

Leeper TJ (2020). PACKAGENAME: An R Package. R package version 0.2.1.

Corresponding BibTeX entry:

  @Manual{,
    title = {PACKAGENAME: An R Package},
    author = {Thomas J. Leeper},
    year = {2020},
    note = {R package version 0.2.1},
  }