To cite package ‘Mega2R’ in publications use:

  Baron RV, Weeks DE (2023). _Mega2R: Accessing and Processing a
  'Mega2' Genetic Database_. R package version 1.1.0,
  <https://CRAN.R-project.org/package=Mega2R>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Mega2R: Accessing and Processing a 'Mega2' Genetic Database},
    author = {Robert V. Baron and Daniel E. Weeks},
    year = {2023},
    note = {R package version 1.1.0},
    url = {https://CRAN.R-project.org/package=Mega2R},
  }