To cite package ‘ggbiplot’ in publications use:

  Vu VQ, Friendly M (2024). _ggbiplot: A Grammar of Graphics
  Implementation of Biplots_. R package version 0.6.3, ,
  <https://github.com/friendly/ggbiplot>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ggbiplot: A Grammar of Graphics Implementation of Biplots},
    author = {Vincent Q. Vu and Michael Friendly},
    year = {2024},
    note = {R package version 0.6.3, 
},
    url = {https://github.com/friendly/ggbiplot},
  }