To cite the mvnfast package in publications use:
Matteo Fasiolo. An introduction to mvnfast (2016). R package version 0.1.6.
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 0.1.6.},
author = {Matteo Fasiolo},
year = {2016},
url = {https://CRAN.R-project.org/package=mvnfast},
}