To cite the 'TAM' package in publications use:

Robitzsch, A., Kiefer, T., & Wu, M. (2018). TAM: Test analysis modules. R package version 3.0-21. https://CRAN.R-project.org/package=TAM

Corresponding BibTeX entry:

  @Manual{,
    title = {TAM: Test analysis modules},
    author = {Alexander Robitzsch and Thomas Kiefer and Margaret Wu},
    year = {2018},
    note = {R package version 3.0-21},
    url = {https://CRAN.R-project.org/package=TAM},
  }