To cite package ‘intervalpsych’ in publications use:

  Kloft M, Siepe B (2025). _intervalpsych: Analyzing Interval Data in
  Psychometrics_. R package version 0.1.0,
  <https://CRAN.R-project.org/package=intervalpsych>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {intervalpsych: Analyzing Interval Data in Psychometrics},
    author = {Matthias Kloft and Björn S. Siepe},
    year = {2025},
    note = {R package version 0.1.0},
    url = {https://CRAN.R-project.org/package=intervalpsych},
  }