To cite package ‘tsissm’ in publications use:

  Galanos A (2025). _tsissm: Linear Innovations State Space Unobserved
  Components Model_. R package version 1.0.2,
  <https://github.com/tsmodels/tsissm>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {tsissm: Linear Innovations State Space Unobserved Components Model},
    author = {Alexios Galanos},
    year = {2025},
    note = {R package version 1.0.2},
    url = {https://github.com/tsmodels/tsissm},
  }