To cite package ‘Matrix’ in publications use:

  Bates D, Maechler M, Jagan M (2024). _Matrix: Sparse and Dense Matrix
  Classes and Methods_. R package version 1.8-0,
  <https://r-forge.r-project.org/projects/matrix>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Matrix: Sparse and Dense Matrix Classes and Methods},
    author = {Douglas Bates and Martin Maechler and Mikael Jagan},
    year = {2024},
    note = {R package version 1.8-0},
    url = {https://r-forge.r-project.org/projects/matrix},
  }