SEARCH

SEARCH BY CITATION

REFERENCES

  • Barkman, J. J. (1958). Phytosociology and Ecology of Cryptogamic Epiphytes. Assen, Netherlands.
  • Department of Scientific and Industial Research (1966). National Survey of Smoke and Sulphur Dioxide: Instruction Manual. Warren Springs Laboratory, Stevenage .
  • Gilbert, O. L. (1968a). Bryophytes as indicators of air pollution in the Tyne Valley. New Phytol., 67, 15.
  • Gilbert, O. L. (1968b). Biological indicators of air pollution. Ph.D. thesis, University of Newcastle upon Tyne.
  • Gilbert, O. L. (1970). Further studies on the effect of sulphur dioxide on lichens and bryophtes. New Phytol., 69, 605627.
  • Lines, R. (1967). Atmospheric pollution in the Pennines in relation to tree growth. Talk to British Association, Leeds .
  • Laundon, J. R. (1967). A study of the lichen flora of London. Lichenologist, 3, 277.
  • Stratmann, H. (1963). Field trials for the determination of SO2 effects on vegetation. II. Measurement and assessment of SO2 ground level concentrations. ForschBer. Landes NRhein-Westf., No. 1184 (Koln and Oplanden, 1963).