To cite package ‘gridOT’ in publications use:

  Groppe M (2022). _gridOT: Approximate Optimal Transport Between
  Two-Dimensional Grids_. R package version 1.0.1,
  <https://CRAN.R-project.org/package=gridOT>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {gridOT: Approximate Optimal Transport Between Two-Dimensional Grids},
    author = {Michel Groppe},
    year = {2022},
    note = {R package version 1.0.1},
    url = {https://CRAN.R-project.org/package=gridOT},
  }