Howto cite postgresql in scientific publications?

Hi,

Is there an official way to cite PostgreSQL in scientific publications?

This might sound somewhat strange to some of you, but e.g. the R project
(http://www.r-project.org, open source environment for statistical
computing as a side note) has a FAQ entry like this:

2.8 Citing R

To cite R in publications, use

@Manual{,
title = {R: A language and environment for statistical
computing},
author = {{R Development Core Team}},
organization = {R Foundation for Statistical Computing},
address = {Vienna, Austria},
year = 2004,
note = {3-900051-07-0},
url = {http://www.R-project.org}
}

Citation strings (or BibTeX entries) for R and R packages can also be obtained
by citation().

Is there something similar "official" for PostgreSQL?

Regards,
Daniel