%0 Generic %D 1991 %T Physiological effects of long term exposure to low concentrations of SO2 and NH3 on poplar leaves. %A van Hove, L.W.A. %A van Kooten, O. %A van Wijk, K.J %A Vredenberg, W.J. %A Adema, E.H. %A Pieters, G.A. %B Plant Physiology %V 82 %P 32-40 %G eng