Schneider, B. U., Meyer, J., Schulze, E. D., & Zech, W. (1989). Root and mycorrhizal
development in healthy and declining Norway spruce stands. In E.-D. Schulze, O. L. Lange, & R. Oren (Eds.),
Forest Decline and Air Pollution, Ecological Studies (pp. 370-391). Berlin, Heidelberg:
Springer.