To cite package ‘regplot’ in publications use:

  Marshall R (2020). _regplot: Enhanced Regression Nomogram Plot_. R
  package version 1.1, <https://CRAN.R-project.org/package=regplot>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {regplot: Enhanced Regression Nomogram Plot},
    author = {Roger Marshall},
    year = {2020},
    note = {R package version 1.1},
    url = {https://CRAN.R-project.org/package=regplot},
  }