To cite package ‘SOP’ in publications use:

Rodriguez-Alvarez M, Oviedo de la Fuente M (2023). SOP: Generalised Additive P-Spline Regression Models Estimation. R package version 1.0-1, https://CRAN.R-project.org/package=SOP.

Corresponding BibTeX entry:

  @Manual{,
    title = {SOP: Generalised Additive P-Spline Regression Models
      Estimation},
    author = {Maria Xose Rodriguez-Alvarez and Manuel {Oviedo de la
      Fuente}},
    year = {2023},
    note = {R package version 1.0-1},
    url = {https://CRAN.R-project.org/package=SOP},
  }