To cite sdstudio in publications use:

  Hu P, Helveston J, Bunea B (2025). _sdstudio: Companion GUI for the
  surveydown survey platform_. R package, <https://surveydown.org/>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {sdstudio: Companion GUI for the surveydown survey platform},
    author = {Pingfan Hu and John Paul Helveston and Bogdan Bunea},
    year = {2025},
    note = {R package},
    url = {https://surveydown.org/},
  }