To cite the mvnfast package in publications use:
Fasiolo M (2014). An introduction to mvnfast. R package version 0.2.8.. University of Bristol. https://CRAN.R-project.org/package=mvnfast.
As mvnfast is often updated, you may want to cite its version number. Find it with 'help(package=mvnfast)'.
Corresponding BibTeX entry:
@Manual{,
title = {An introduction to mvnfast. R package version 0.2.8.},
author = {Matteo Fasiolo},
organization = {University of Bristol},
year = {2014},
url = {https://CRAN.R-project.org/package=mvnfast},
}