To cite package 'SCI' in publications use:

Gudmundsson L, Stagge JH (2016). SCI: Standardized Climate Indices such as SPI, SRI or SPEI. R package version 1.0-2.

Stagge JH, Tallaksen LM, Gudmundsson L, van Loon A, Stahl K (2015). “Candidate Distributions for Climatological Drought Indices (SPI and SPEI).” International Journal of Climatology, 35, 4027-4040. doi:10.1002/joc.4267.

Stagge JH, Tallaksen LM, Gudmundsson L, van Loon A, Stahl K (2016). “Response to comment on 'Candidate Distributions for Climatological Drought Indices (SPI and SPEI)'.” International Journal of Climatology, 36, 2132-2138. doi:10.1002/joc.4564.

Corresponding BibTeX entries:

  @Manual{,
    title = {SCI: Standardized Climate Indices such as SPI, SRI or
      SPEI},
    author = {Lukas Gudmundsson and James H. Stagge},
    year = {2016},
    note = {R package version 1.0-2},
  }

  @Article{,
    title = {Candidate Distributions for Climatological Drought Indices
      (SPI and SPEI)},
    author = {J. H. Stagge and L. M. Tallaksen and L. Gudmundsson and
      A. {van Loon} and K. Stahl},
    journal = {International Journal of Climatology},
    year = {2015},
    volume = {35},
    pages = {4027-4040},
    doi = {10.1002/joc.4267},
  }

  @Article{,
    title = {Response to comment on 'Candidate Distributions for
      Climatological Drought Indices (SPI and SPEI)'},
    author = {J. H. Stagge and L. M. Tallaksen and L. Gudmundsson and
      A. {van Loon} and K. Stahl},
    journal = {International Journal of Climatology},
    year = {2016},
    volume = {36},
    pages = {2132-2138},
    doi = {10.1002/joc.4564},
  }