To cite bayestestR in publications use:

  Makowski, D., Ben-Shachar, M., & Lüdecke, D. (2019). bayestestR:
  Describing Effects and their Uncertainty, Existence and Significance
  within the Bayesian Framework. Journal of Open Source Software,
  4(40), 1541. doi:10.21105/joss.01541

A BibTeX entry for LaTeX users is

  @Article{,
    title = {bayestestR: Describing Effects and their Uncertainty, Existence and Significance within the Bayesian Framework.},
    author = {Dominique Makowski and Mattan S. Ben-Shachar and Daniel Lüdecke},
    journal = {Journal of Open Source Software},
    doi = {10.21105/joss.01541},
    year = {2019},
    number = {40},
    volume = {4},
    pages = {1541},
    url = {https://joss.theoj.org/papers/10.21105/joss.01541},
  }