To cite mi in publications use:

Yu-Sung Su, Andrew Gelman, Jennifer Hill, Masanao Yajima (2011). Multiple Imputation with Diagnostics (mi) in R: Opening Windows into the Black Box. Journal of Statistical Software, 45(2), 1-31. URL http://www.jstatsoft.org/v45/i02/.

Corresponding BibTeX entry:

  @Article{,
    title = {Multiple Imputation with Diagnostics ({mi}) in {R}:
      Opening Windows into the Black Box},
    author = {Yu-Sung Su and Andrew Gelman and Jennifer Hill and
      Masanao Yajima},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {45},
    number = {2},
    pages = {1--31},
    url = {http://www.jstatsoft.org/v45/i02/},
  }