To cite the 'ASSA' package in publications use:

de Carvalho M, Martos G (2020). ASSA: Applied Singular Spectrum Analysis. R package version 2.0.

Corresponding BibTeX entry:

  @Manual{,
    title = {ASSA: Applied Singular Spectrum Analysis},
    author = {M. {de Carvalho} and G. Martos},
    year = {2020},
    note = {R package version 2.0},
  }