@booklet {1418, year = {Submitted}, keywords = {af(st)y, air-pollution, aot40, critical flux versus exposure, exposure indexes, gas-exchange, lettuce, plants, protect vegetation, responses, spring wheat, standard, stomatal conductance, white clover}, author = {Goumenaki, E. and Fernandez, I. G. and Papanikolaou, A. and Papadopoulou, D. and Askianakis, C. and Kouvarakis, G. and Barnes, J.} }