To cite package ‘gek’ in publications use:

  van Meegen C (2025). _gek: Gradient-Enhanced Kriging_. R package
  version 1.1.0, <https://CRAN.R-project.org/package=gek>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {gek: Gradient-Enhanced Kriging},
    author = {Carmen {van Meegen}},
    year = {2025},
    note = {R package version 1.1.0},
    url = {https://CRAN.R-project.org/package=gek},
  }