To cite package ‘revealjs’ in publications use:

  Allaire J, El Hattab H (2017). _revealjs: R Markdown Format for
  'reveal.js' Presentations_. R package version 0.9.1.9007,
  <https://github.com/rstudio/revealjs>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {revealjs: R Markdown Format for 'reveal.js' Presentations},
    author = {JJ Allaire and Hakim {El Hattab}},
    year = {2017},
    note = {R package version 0.9.1.9007},
    url = {https://github.com/rstudio/revealjs},
  }