To cite package ‘prefio’ in publications use:

  Everest F, Turner H, Vukcevic D (2023). _prefio: Structures for
  Preference Data_. R package version 0.1.1, ,
  <https://github.com/fleverest/prefio>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {prefio: Structures for Preference Data},
    author = {Floyd Everest and Heather Turner and Damjan Vukcevic},
    year = {2023},
    note = {R package version 0.1.1, 
},
    url = {https://github.com/fleverest/prefio},
  }