1. 2. Burton, M.A.S.Biological Monitoring of Environmental Contaminants (Plants), Monitoring and Assessment Research Centre, Technical Report No. 32, King′s College, London, 1986.
2. 3. Seaward, M.R.D. “The Use and Abuse of Heavy Metal Bioassays of Lichens for Environmental Monitoring”, in Spaleny, J. (Ed.),Proceedings of the Third International Conference Bioindicatores Deteriorisationis Regionis, September 1977, Liblice, Academia, Praha, 1980, pp. 375‐84.
3. 4. Seaward, M.R.D.The Use and Abuse of Bio‐indicators in Air Pollution Surveys, Standing Conference of Co‐operating Bodies 88/5, Warren Spring Laboratory, Stevenage, 1977.
4. 5. Herzig, R. and Urech, M. “Flechten als Bioindikatoren”,Bibliotheca Lichenologica, Vol. 43, 1991, pp. 1‐283.
5. 7. Thoni, L., Schmid‐Grob, I. and Hertz, J. “Analytische Vergleichsmessungen an Moosen und an Bergerhoffproben‐aum Aussagewert von Schwermetallmessungen mit Hilfe von Moosen als Biomonitoren”,VDI Berichte, Vol. 901, 1991, pp. 705‐10.