@article {715, title = {Inter actions of elevated CO2, NH3 and O3 on mycorrhizal infection, gas exchange and N metabolism in seedlings of Scots pine}, journal = {Plant and Soil }, volume = {176}, year = {1995}, pages = {107-116}, author = {Pirez-Soba, M. and Dueck, T.A. and Puppi, G. and Kuiper, P.J.C.} }