• Aplin, P. S. & Hill, D. J. (1979) Growth analysis of circular lichen thalli. Journal of Theoretical Biology, 78, 347363.
  • Armstrong, R. A. (1973) Seasonal growth and growth rate colony size relationships in six species of saxicolous lichens. The New Phytologist, 72, 10231030.
  • Armstrong, R. A. (1976) The influence of the frequency of wetting and drying on the radial growth of three saxicolous lichens in the field. The New Phytologist, 77, 719724.
  • Armstrong, R. A. (1979) Growth and regeneration of lichen thalli with the central portions artificially removed. Environmental and Experimental Botany, 19, 175178.
  • Armstrong, R. A. (1981) Field experiments on the dispersal, establishment and colonization of lichens on a slate rock surface. Environmental and Experimental Botany, 21, 115120.
  • Armstrong, R. A. (1982) Competition between three foliose species of Parmelia (Lichens). The New Phytologist, 90, 6772.
  • Farrar, J. F. & Smith, D. C. (1976) Ecological physiology of the lichen Hypogymnia physodes 111. The importance of the rewetting phase. The New Phytologist, 77, 115125.
  • Hale, M. E. (1970) Single lobe growth rate patterns in the lichen Parmelia caperata. Bryologist, 73, 7281.
  • Hale, M. E. (1983) The Biology of Lichens. Contemporary Biology Series, Arnold, London .
  • Hooker, T. N. (1980) Lobe growth and marginal zonation in crustose lichens. Lichenologist, 12, 313323.
  • Jahns, H. M. (1973) Anatomy, morphology, and development. In: The Lichens (Eds. V.Ahmadjian & M. E.Hale), pp. 358, Academic Press, New York and London .
  • Lawrey, J. D. & Hale, M. E. (1977) Studies on lichen growth rate at Plummers Island, Maryland. Proceeding of the Biological Society of Washington, 90, 698725.
  • Phillips, H. C. (1969) Annual growth rates of three species of foliose lichens determined photographically. Bulletin of the Torrey Botanical Club, 96, 202206.
  • Ridgman, W. J. (1975) Experimentation in Biology. Blackie, Glasgow and London .
  • Snedecor, G. W. & Cochran, W. J. (1967) Statistical Methods. Sixth Edition, Iowa State University Press.