To cite package ‘ggtrendline’ in publications use:

Mei W, Yu G, Greenwell B (2022). ggtrendline: Add Trendline and Confidence Interval to 'ggplot'. R package version 1.0.3, https://github.com/phdmeiwp/ggtrendline.

Corresponding BibTeX entry:

  @Manual{,
    title = {ggtrendline: Add Trendline and Confidence Interval to
      'ggplot'},
    author = {Weiping Mei and Guangchuang Yu and Brandon M. Greenwell},
    year = {2022},
    note = {R package version 1.0.3},
    url = {https://github.com/phdmeiwp/ggtrendline},
  }