To cite approxOT in publications use:

Dunipace E (2021). approxOT: approximate optimal transport. R package version 0.1, https://github.com/ericdunipace/approxOT.

Corresponding BibTeX entry:

  @Manual{,
    title = {{approxOT}: approximate optimal transport},
    author = {Eric A. Dunipace},
    year = {2021},
    note = {R package version 0.1},
    url = {https://github.com/ericdunipace/approxOT},
  }