Choi, D.S., Quoreshi, A.M., Maruyama, Y., Jin, H.O. and Koike, T.  2005.  Effect of ectomycorrhizal infection on growth and photosynthetic characteristics of Pinus densiflora seedlings grown under elevated CO2 concentrations.  Photosynthetica 43: 223-229.

Norisada, M., Motoshige, T., Kojima, K. and Tange, T. 2006. Effects of phosphate supply and elevated CO2 on root acid phosphatase activity in Pinus densiflora seedlings. Journal of Plant Nutrition and Soil Science 169: 274-279.