To cite the 'patternplot' package in publications use:

  Chunqiao Luo, Shasha Bai(2020). Versatile Pie Charts, Ring Charts,
  Bar Charts and Box Plots using Patterns, Colors and Images. R package
  version 1.0.0.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Versatile Pie Charts, Ring Charts, Bar Charts and Box Plots
using Patterns, Colors and Images},
    author = {Chunqiao Luo and Shasha Bai},
    year = {2020},
    note = {R package version 1.0.0},
  }