To cite spfilteR in publications use:

Juhl, Sebastian (2021): spfilteR: An R Package for Semiparametric Spatial Filtering with Eigenvectors in (Generalized) Linear Models. The R Journal. 13(2): 450-459.

Corresponding BibTeX entry:

  @Article{,
    title = {spfilteR: An R Package for Semiparametric Spatial
      Filtering with Eigenvectors in (Generalized) Linear Models},
    author = {{Sebastian Juhl}},
    journal = {The R Journal},
    year = {2021},
    volume = {13},
    number = {2},
    pages = {450-459},
    url = {https://doi.org/10.32614/RJ-2021-085},
  }