To cite 'ordinal' in publications use:
Christensen R (2023). ordinal—Regression Models for Ordinal Data. R package version 2023.12-4.1, https://CRAN.R-project.org/package=ordinal.
Corresponding BibTeX entry:
@Manual{, title = {ordinal---Regression Models for Ordinal Data}, author = {Rune H. B. Christensen}, year = {2023}, note = {R package version 2023.12-4.1}, url = {https://CRAN.R-project.org/package=ordinal}, }