To cite mongolite in publications use:

Jeroen Ooms (2014). The jsonlite Package: A Practical and Consistent Mapping Between JSON Data and R Objects. arXiv:1403.2805 [stat.CO] http://arxiv.org/abs/1403.2805

Corresponding BibTeX entry:

  @Article{,
    title = {The jsonlite Package: A Practical and Consistent Mapping
      Between JSON Data and R Objects},
    author = {Jeroen Ooms},
    journal = {arXiv:1403.2805 [stat.CO]},
    year = {2014},
    url = {http://arxiv.org/abs/1403.2805},
  }