To cite BFpack in publications use:

  Joris Mulder, Donald R. Williams, Xin Gu, Andrew Tomarken, Florian
  B{"o}ing-Messing, Anton Olsson-Collentine, Marlyne Meijerink, Janosch
  Menke, Robbie van Aert, Jean-Paul Fox, Herbert Hoijtink, Yves
  Rosseel, Eric-Jan Wagenmakers, Caspar van Lissa (2021). BFpack:
  Flexible Bayes Factor Testing of Scientific Theories in R. Journal of
  Statistical Software, 100(18), 1-63. doi:10.18637/jss.v100.i18

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{BFpack}: Flexible Bayes Factor Testing of Scientific Theories in {R}},
    author = {Joris Mulder and Donald R. Williams and Xin Gu and Andrew Tomarken and Florian B{\"o}ing-Messing and Anton Olsson-Collentine and Marlyne Meijerink and Janosch Menke and Robbie {van Aert} and Jean-Paul Fox and Herbert Hoijtink and Yves Rosseel and Eric-Jan Wagenmakers and Caspar {van Lissa}},
    journal = {Journal of Statistical Software},
    year = {2021},
    volume = {100},
    number = {18},
    pages = {1--63},
    doi = {10.18637/jss.v100.i18},
  }