To cite package ‘ILSAmerge’ in publications use:

  Christiansen A (2024). _ILSAmerge: Merge and Download International
  Large-Scale Assessments (ILSA) Data_. R package version 1.3.0,
  <https://CRAN.R-project.org/package=ILSAmerge>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ILSAmerge: Merge and Download International Large-Scale Assessments (ILSA)
Data},
    author = {Andrés Christiansen},
    year = {2024},
    note = {R package version 1.3.0},
    url = {https://CRAN.R-project.org/package=ILSAmerge},
  }