Chen, X., Tu, C., Burton, M.G., Watson, D.M., Burkey, K.O. and Hu, S. 2007. Plant nitrogen acquisition and interactions under elevated carbon dioxide: impact of endophytes and mycorrhizae. Global Change Biology 13: 1238-1249.

Garten Jr., C.T., Classen, A.T., Norby, R.J., Brice, D.J., Weltzin, J.F. and Souza, L. 2008. Role of N2-fixation in constructed old-field communities under different regimes of [CO2], temperature, and water availability. Ecosystems 11: 125-137.

Hodge, A. and Millard, P. 1998. Effect of elevated CO2 on carbon partitioning and exudate release from Plantago lanceolata seedlings. Physiologia Plantarum 103: 280-286.

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.

Maestre, F.T. and Reynolds, J.F. 2007. Biomass responses to elevated CO2, soil heterogeneity and diversity: an experimental assessment with grassland assemblages. Oecologia 151: 512-520.

Wulff, R.D. and Alexander, H.M. 1985. Intraspecific variation in the response to CO2 enrichment in seeds and seedlings of Plantago lanceolata L. Oecologia 66: 458-460.