World Resources Institute
Fertile Ground: Nutrient Trading's potential to cost-effectively improve water quality (2000) - Paul Faeth, World Resources Institute - Link
"Awakening the "Dead Zone": An investment for agriculture, water quality and climate change" - Suzie Greenhalgh and Amanda Sauer, WRI Issue Brief (2003)- link includes presentations on P, N and CO2 trading and full text document.
Nutrient
Trading: Improving water quality through market-based
incentives, World Resources Institute (2004)
A Guide to market-based approaches to water quality (2006). World Resources Institute (pdf)
Paying for Environmental Performance: Using reverse auctions to allocate funding for conservation - WRI Policy Note no 3 (Jan. 2007) - pdf
Paying for Environmental Performance: Estimating the environmental outcomes of agricultural best management practices - WRI Policy Note no 4 (May 2007) - pdf.