citing postgresql?

hi all,

exists a common citation for the postgresql-project, like e.g. for the
R-project:

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 = 2006,
note = {{ISBN} 3-900051-07-0},
url = {http://www.R-project.org}
}

thanks for every help
christian