To cite the micromap package in publications use:

Payton QC, McManus MG, Weber MH, Olsen AR, Kincaid TM (2015). “micromap: A Package for Linked Micromaps.” Journal of Statistical Software, 63(2), 1–16. https://www.jstatsoft.org/article/view/v063i02.

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 = {https://www.jstatsoft.org/article/view/v063i02},
  }