To cite the psychTools package in publications use:

Revelle W (2020). psychTools:Tools to Accompany the 'psych; Package for Psychological Research . Northwestern University, Evanston, Illinois. R package version 2.0.6, https://CRAN.R-project.org/package=psychTools.

Corresponding BibTeX entry:

  @Manual{,
    title = {psychTools:Tools to Accompany the 'psych; Package for
      Psychological Research },
    author = {William Revelle},
    organization = { Northwestern University},
    address = { Evanston, Illinois},
    year = {2020},
    note = {R package version 2.0.6},
    url = {https://CRAN.R-project.org/package=psychTools},
  }