@article {Powers:September 2002:0016-7061:141,
	author = "Powers J.S.",
	author = "Schlesinger W.H.",
	title = "Geographic and vertical patterns of stable carbon isotopes in tropical rain forest soils of Costa Rica",
	journal = "Geoderma",
	volume = "109",
	year = "September 2002",
	abstract = "",
	pages = "141-160(20)",
	url = "http://www.ingentaconnect.com/content/els/00167061/2002/00000109/00000001/art00148"
	doi = "doi:10.1016/S0016-7061(02)00148-9"
}