To cite package 'iopysch' in publications use:

Goebl, A. P., Jones, J. A., and Beatty, A. S. (2016). iopsych: Methods for industrial/organizational psychology. R package version 0.90

Corresponding BibTeX entry:

  @Manual{,
    title = {iopsych: Methods for industrial/organizational
      psychology.},
    author = {Allen P. Goebl and Jeff A. Jones and Adam S. Beatty},
    year = {2016},
    note = {version 0.90},
  }