@book {763, title = {Growth of Norway spruce (Picea abies) in relation to the AOT40 index.}, year = {2002}, type = {Background paper presented at the UNECE Workshop Establishing Ozone Critical Levels II, Goteborg November 2002}, author = {Skarby, L. and Ottoson, S. and Karlsson, P.E. and Wallin, G. and Sellden, G. and Medin, E. and Pleijel, H.} }