To cite ProAE in publications use:

Langlais B, Klanderman M, Noble B, Voss M, Dueck A (2020). ProAE: Tools for PRO-CTCAE Scoring, analysis, and graphical display. https://CRAN.R-project.org/.

Corresponding BibTeX entry:

  @Manual{proae,
    title = {ProAE: Tools for PRO-CTCAE Scoring, analysis, and
      graphical display},
    author = {Blake Langlais and Molly Klanderman and Brie Noble and
      Molly Voss and Amylou Dueck},
    year = {2020},
    url = {https://CRAN.R-project.org/},
  }