a character(1) vector giving the name of a package. If NULL, a citation for R is produced.
author
Include author name
title
Include title of package
org
Include organization name
address
Include address
volume
Include volume
year
include year of publication
note
include the note on the citation.
Details
Not every option is populated in every package.
Future improvements might include automatic detection of NULL fields,
but for now, observing the output with all the options set to TRUE
will tell you which ones are empty.