1. The influence of air pollution on bryophytes and lichens;Barkman,1969
2. Fluorosis in cattle: Occurrence and effects in industrial areas in England and Wales 1954–1957;Burns,1964
3. Determination of total sulphur in plant material;Cunningham;Chemy. Ind.,1962
4. Air pollution in the Bedfordshire brickfields;Department of the Environment;Department of the Environment Report,1980
5. Biological indicators of air pollution;Gilbert,1968