Ellsworth, D.S., Reich, P.B., Naumburg, E.S., Koch, G.W., Kubiske, M.E. and Smith, S.D.  2004.  Photosynthesis, carboxylation and leaf nitrogen responses of 16 species to elevated pCO2 across four free-air CO2 enrichment experiments in forest, grassland and desert.  Global Change Biology 10: 2121-2138.

Housman, D.C., Naumburg, E., Huxman, T.E., Charlet, T.N., Nowak, R.S. and Smith, S.D. 2006. Increases in desert shrub productivity under elevated carbon dioxide vary with water availability. Ecosystems 9: 374-385.

Naumburg, E., Housman, D.C., Huxman, T.E., Charlet, T.N., Loik, M.E. and Smith, S.D.  2003.  Photosynthetic responses of Mojave Desert shrubs to free air CO2 enrichment are greatest during wet years.  Global Change Biology 9: 276-285.