Wöllecke, J., Münzenberger, B., Hüttl, R. F. J. (1999): Some Effects of N on Ectomycorrhizal Diversity of Scots Pine (Pinus Sylvestris L.) in Northeastern Germany. - Water, Air and Soil Pollution, 116, 1-2, 135-140.https://doi.org/10.1023/A:1005211011835