To cite the onion package in publications use:

Hankin, R. K. S. (2006). Normed division algebras with R: Introducing the onion package, R News, volume 6, number 2, pages 49-52

Corresponding BibTeX entry:

  @Article{,
    title = {{Normed division algebras with R: Introducing the onion
      package}},
    author = {{Robin K. S. Hankin}},
    journal = {R News},
    year = {2006},
    volume = {6},
    number = {2},
    pages = {49-52},
  }