To cite hwsdr in publications use:

Hufkens (2021). The hwsdr package: an interface to ORNL DAAC HWSD API endpoints

Corresponding BibTeX entry:

  @Misc{,
    title = {The hwsdr package: an interface to ORNL DAAC HWSD API
      endpoints},
    author = {Koen Hufkens},
    year = {2021},
    url = {https://bluegreen-labs.github.io/hwsdr/},
  }