• Bidwell, R. G. S. (1977). Photosynthesis and light and dark respiration in freshwater algae. Canadian Journal of Botany, 55, 809818.
  • Birmingham, B. C., Coleman, J. R. & Colman, B. (1982). Measurement of photorespiration in algae. Plant Physiology, 69, 259262.
  • Brock, T. D. (1975). Effect of water potential on a Microcoleus (Cyanophyceae) from a desert crust. Journal of Phycology, 11, 316320.
  • Busby, J. R., & Whitfield, D. W. A. (1978). Water potential, water content and net assimilation of some boreal forest mosses. Canadian Journal of Botany, 56, 11511158.
  • Drew, E. A. & Smith, D. S. (1967). Studies in the physiology of lichens. VIII. Movement of glucose from alga to fungus during photosynthesis in the thallus of Peltigera polydactyla. New Phytologist, 66, 389400.
  • Hogetsu, D. S. & Miyachi, S. (1977). Effect of CO2 concentration during growth and subsequent photosynthetic fixation in Chlorella. Plant Cell Physiology, 18, 347352.
  • Kershaw, K. A. & Macfarlane, J. D. (1982). Physiological-environmental interactions in lichens. XIII. Seasonal constancy of nitrogenase activity, net photosynthesis, and respiration in Collema furfuraceum (AM.)DR. New Phytologist, 90, 723735.
  • Kriedemann, P. E. & Downton, J. S. (1981). Photosynthesis. In: The Physiology and Biochemistry of Drought Resistance in Plants (Ed. by L. G.Paleg & D.Aspinall), pp. 283314. Academic Press, London .
  • Larson, D. W. & Kershaw, K. A. (1975). Measurement of CO2 exchange in lichens: a new method. Canadian Journal of Botany, 53, 15351541.
  • Lloyd, N. D. H., Canvin, D. T. & Culver, D. A. (1977). Photosynthesis and photo respiration in algae. Plant physiology, 59, 936940.
  • Macfarlane, J. D. & Kershaw, K. A. (1982). Physiological-environmental interactions in lichens. XIV. The environmental control of glucose movement from alga to fungus in Peltigera polydactyla, P. rufescens and Collema furfuraceum. New Phytologist, 91, 93101.
  • Ludwig, L. J. & Calvin, D. T. (1971). An open gas exchange system for the simultaneous measurement of the CO2 and 14CO2 fluxes from leaves. Canadian Journal of Botany, 49, 12991313.
  • Raven, J. A. & Glidwell, S. M. (1978). C4 characteristics of photosynthesis in the C3 alga Hydrodictyon africanum. Plant Cell and Environment, 1, 185197.
  • Rychert, R. C. & Skujins, J. (1974). Nitrogen fixation by blue-green algae-lichen crusts in the Great Basic Desert. Soil Science Society of America Proceedings, 38, 768771.
  • Smith, D. C. (1980). Mechanisms of nutrient movement between lichen symbionts, In: Cellular Interactions in Symbiosis and Parasitism. (Ed. by C. B.Cook, P. W.Pappas & E. D.Rudolph), p. 305. Ohio State University Press, Columbus , Ohio .
  • Snelgar, W. P. & Green, T. G. A. (1981). Carbon dioxide exchange in lichens: low carbon dioxide compensation levels and lack of apparent photorespiratory activity in some lichens. The Bryologist, 83 505507.
  • Steward, F. C., Craven, G. H., Weerasinghe, S. P. R. & Bidwell, R. G. S. (1971). Effects of prior environmental conditions on the subsequent uptake and release of carbon dioxide in the light. Canadian Journal of Botany, 49, 19992007.