To cite package tmvtnorm in publications use:

Stefan Wilhelm, Manjunath B G (2013). tmvtnorm: Truncated Multivariate Normal and Student t Distribution. R package version 1.4-8.

Corresponding BibTeX entry:

  @Manual{,
    title = {{tmvtnorm}: Truncated Multivariate Normal and Student t
      Distribution},
    author = {Stefan Wilhelm and Manjunath B G},
    year = {2013},
    note = {R package version 1.4-8},
    url = {http://CRAN.R-project.org/package=tmvtnorm},
  }