To cite package 'tubern' in publications use:

Gaurav Sood (2017). tubern: R Client for the Youtube Analytics and Reporting API. R package version 0.1.0.

Corresponding BibTeX entry:

  @Manual{,
    title = {tubern: R Client for the Youtube Analytics and Reporting
      API},
    author = {Gaurav SOod},
    year = {2017},
    note = {R package version 0.1.0},
  }