To cite package ‘GetDFPData’ in publications use:

  Perlin M (2021). _GetDFPData: Reading Annual Financial Reports from
  Bovespa's DFP, FRE and FCA System_. R package version 1.6,
  <https://CRAN.R-project.org/package=GetDFPData>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {GetDFPData: Reading Annual Financial Reports from Bovespa's DFP, FRE and FCA
System},
    author = {Marcelo Perlin},
    year = {2021},
    note = {R package version 1.6},
    url = {https://CRAN.R-project.org/package=GetDFPData},
  }