reference: Retrieve citation of data object
In chronosphere: Earth System History Variables

The function prints or returns the citation string of a chosen object/item.

1	reference(dat, var = NULL, ver = NULL, print = TRUE, prefix = "")

`dat`	(`characater`) Object downloaded with `fetch` or the database identifier string.
`var`	(`character`) In case `dat` is `character`, the variable identifier.
`ver`	(`character`) In case `dat` is `character`, the version identifier.
`print`	(`logical`) Should the citations be printed to the console, or returned as a `character` vector.
`prefix`	(`characater`) In case the output is printed on the console. Use this to include a prefix before every entry.