7 De Vries, W Leip, A Reinds, G.J Kros, J Lesschen, J.P Bouwman, A.F Grizzetti, B Bouraoui, F Butterbach Bahl, K Winiwarter, W 2010 In European Nitrogen Assessment, Chapter - Geographic variation in nitrogen budgets in agricultural and other terrestrial ecosystems over Europe Cambridge University Press Chapter 15