Tybirk, K., Jakobsen, K.
, Strandberg, B., Gustafsson, L. (red.), Weslien, J.-O. (red.), Palmér, C. H. (red.) & Sennerby-Forsse, L. (red.) (1998).
Understory Vegetation in Norway Spruce (Picea abies (L.) Karst.) Stands in Relation to Management and Environmental Parameters. I
SkogForsk Report No 1, 1998 (s. 141-142). Uppsala: The Forestry Research Institute of Sweden.
Sørensen, P. B., Carlsen, L., Mogensen, B. B., Sørensen, P. B. (red.), Carlsen, L. (red.)
, Mogensen, B. B. (red.), Brüggemann, R. (red.), Luther, B. (red.), Pudenz, S. (red.), Simon, U. (red.), Halfon, E. (red.), Bittner, T. (red.), Voigt, K. (red.), Welzl, G. (red.) & Rediske, F. (red.) (2000).
Uncertainty in Partial Order Ranking. I
NERI Technical Report (s. 45-52). National Environmental Research Institute.