Barnard, R., Barthes, L., Le Roux, X. and Leadley, P.W. 2004. Dynamics of nitrifying activities, denitrifying activities and nitrogen in grassland mesocosms as altered by elevated CO2. New Phytologist 162: 365-376.

Drigo, B., van Veen, J.A. and Kowalchuk, G.A. 2009. Specific rhizosphere bacterial and fungal groups respond differently to elevated atmospheric CO2. The ISME Journal 3: 1204-1217.

Hunt, R., Hand, D.W., Hannah, M.A. and Neal, A.M. 1991. Response to CO2 enrichment in 27 herbaceous species. Functional Ecology 5: 410-421.

Hunt, R., Hand, D.W., Hannah, M.A. and Neal, A.M. 1995. Temporal and nutritional influences on the response to elevated CO2 in selected British grasses. Annals of Botany 75: 207-216.