Reich, P.B., Tilman, D., Craine, J., Ellsworth, D., Tjoelker, M.G., Knops, J., Wedin, D., Naeem, S., Bahauddin, D., Goth, J., Bengtson, W. and Lee, T.D.  2001.  Do species and functional groups differ in acquisition and use of C, N and water under varying atmospheric CO2 and N availability regimes?  A field test with 16 grassland species.  New Phytologist 150: 435-448.

Volin, J.C., Reich, P.B. and Givnish, T.J.  1998.  Elevated carbon dioxide ameliorates the effets of ozone on photosynthesis and growth: species respond similarly regardless of photosynthetic pathway or plant functional group.  New Phytologist 138: 315-325.