To cite the metaplus package in publications, please use:

  Beath, K. J. (2016). metaplus: An R Package for the Analysis of
  Robust Meta-Analysis and Meta-Regression, R Journal, 8(1), 5-16. URL:
  https://https://journal.r-project.org/articles/RJ-2016-001/RJ-2016-001.pdf

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{metaplus}: An {R} Package for the Analysis of Robust Meta-Analysis and Meta-Regression},
    author = {K. J. Beath},
    journal = {R Journal},
    volume = {8},
    number = {1},
    pages = {5--16},
    year = {2016},
    url = {https://journal.r-project.org/articles/RJ-2016-001/RJ-2016-001.pdf},
  }