@booklet {RCoreTeam2013,
	title = {R: A Language and Environment for Statistical Computing},
	year = {2013},
	address = {Vienna, Austria},
	url = {http://www.r-project.org},
	author = {{R Core Team}}
}
@booklet {Oksanen2013,
	title = {vegan: Community Ecology Package},
	year = {2013},
	url = {http://cran.r-project.org/package=vegan},
	author = {Oksanen, Jari and Blanchet, F. Guillaume and Kindt, Roeland and Legendre, Pierre and Minchin, Peter R. and O{\textquoteright}Hara, R. B. and Simpson, Gavin L. and Solymos, Peter and Stevens, Henry H. and Wagner, Helene}
}
