To cite package ‘ELMSO’ in publications use:

  Paulson C (2020). _ELMSO: Implementation of the Efficient Large-Scale
  Online Display Advertising Algorithm_. R package version 1.0.1,
  <https://CRAN.R-project.org/package=ELMSO>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ELMSO: Implementation of the Efficient Large-Scale Online Display
Advertising Algorithm},
    author = {Courtney Paulson},
    year = {2020},
    note = {R package version 1.0.1},
    url = {https://CRAN.R-project.org/package=ELMSO},
  }