To cite the micromap package in publications use:

Quinn C. Payton, Michael G. McManus, Marc H. Weber, Anthony R. Olsen, and Thomas M. Kincaid (2015). micromap: A Package for Linked Micromaps. Journal of Statistical Software, 63(2), 1-16. URL http://www.jstatsoft.org/v63/i02/.

Corresponding BibTeX entry:

  @Article{,
    title = {{micromap}: A Package for Linked Micromaps},
    author = {Quinn C. Payton and Michael G. McManus and Marc H. Weber
      and Anthony R. Olsen and Thomas M. Kincaid},
    journal = {Journal of Statistical Software},
    year = {2015},
    volume = {63},
    number = {2},
    pages = {1--16},
    url = {http://www.jstatsoft.org/v63/i02/},
  }