To cite package ‘coop’ in publications use:

  Schmidt D (????). “Co-Operation: Fast Correlation, Covariance, and
  Cosine Similarity.” R package version 0.6-3,
  <https://cran.r-project.org/package=coop>.

A BibTeX entry for LaTeX users is

  @Misc{coop2016,
    title = {{Co-Operation}: Fast Correlation, Covariance, and Cosine Similarity},
    author = {Drew Schmidt},
    note = {{R} package version 0.6-3},
    url = {https://cran.r-project.org/package=coop},
  }

  Schmidt D (2016). _Introducing coop: Fast Covariance, Correlation,
  and Cosine Operations_. R Vignette,
  <https://cran.r-project.org/package=coop>.

A BibTeX entry for LaTeX users is

  @Manual{coop2016guide,
    title = {Introducing {coop}: Fast Covariance, Correlation, and Cosine Operations},
    author = {Drew Schmidt},
    year = {2016},
    note = {{R} Vignette},
    url = {https://cran.r-project.org/package=coop},
  }

  Schmidt D (2016). _Algorithms and Benchmarks for the coop Package_. R
  Vignette, <https://cran.r-project.org/package=coop>.

A BibTeX entry for LaTeX users is

  @Manual{coop2016algos,
    title = {Algorithms and Benchmarks for the {coop} Package},
    author = {Drew Schmidt},
    year = {2016},
    note = {{R} Vignette},
    url = {https://cran.r-project.org/package=coop},
  }