Atkinson, P.W., Clark, J.A., Delany, S., Diagana, C.H., du Feu, C., Fiedler, W., Fransson, T., Gaulthier-Clerc, M., Grantham, M., Gschweng, M., Hagemeijer, W., Helmink, T., Johnson, A., Khomenko, S., Martakis, G., Overdijk, O., Robinson, R.A., Solokha, A., Spina, F., Sylla, S.I., Veen, J. & Visser, D. 2006. Urgent preliminary assessment of ornithological data relevant to the spread avian influenza in Europe. Wetlands International, Wageningen