To cite package ‘EFM’ in publications use:

  Guo G, Zhou Y (2025). _EFM: Elliptical Factor Models_. R package
  version 1.3.0, <https://CRAN.R-project.org/package=EFM>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {EFM: Elliptical Factor Models},
    author = {Guangbao Guo and Yuanyuan Zhou},
    year = {2025},
    note = {R package version 1.3.0},
    url = {https://CRAN.R-project.org/package=EFM},
  }