To cite fitPS in publications use:

  Curran, J. M. (2024) fitPS: Fit Zeta Distributions to Forensic Data.
  
  R package version 1.0.0. https://github.com/jmcurran/fitPS

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {fitPS: Fit Zeta Distributions to Forensic Data},
    author = {J. M. Curran},
    year = {2024},
    note = {R package version 1.0.0},
    url = {https://github.com/jmcurran/fitPS},
  }