Christiansen, E., V. Franceshi, N. Nagy, T. Krekling, A. Berryman, P. Krokene, and H. Solheim. 1999. Traumatic resin duct formation in Norway spruce (Picea abies (L.) Karst.) after wounding or infection with a bark beetle-associated blue-stain fungus, Ceratocystis polonica Siem. Pages 79-89 In Physiology and genetics of tree-phytophage interactions: International Symposium. Proceedings of International Symposium on Physiology and Genetics of Tree-Phytophage Interactions, Gulan, France, August 31 -September 4, 1997. Colloques de l'INRA 90.