To cite the psych package in publications use:

Revelle, W. (2012) psych: Procedures for Personality and Psychological Research Northwestern University, Evanston, http://personality-project.org/r/psych.manual.pdf, 1.2.1

Corresponding BibTeX entry:

  @Manual{,
    title = {psych: Procedures for Psychological, Psychometric, and
      Personality Research},
    author = {William Revelle},
    organization = {Northwestern University},
    address = {Evanston, Illinois},
    year = {2012},
    note = {R package version 1.2.1},
    url = {http://personality-project.org/r/psych.manual.pdf},
  }