To cite photosynthesis in publications use:

Muir CD (2020). “photosynthesis: model C3 photosynthesis.” R package version 1.0.2, https://CRAN.R-project.org/package=photosynthesis.

Corresponding BibTeX entry:

  @Misc{,
    title = {photosynthesis: model {C3} photosynthesis},
    author = {Christopher D Muir},
    note = {R package version 1.0.2},
    year = {2020},
    url = {https://CRAN.R-project.org/package=photosynthesis},
  }