1. Berry, W.L. 1986. Plant factors influencing the use of plant analysis as a tool for biogeochemical prospecting. In: W.L. Carlisle, I.R. Berry, J.R. Watterson (ed).Mineral Exploration: Biological systems and organic matter, Rubey vol. , Prentice-Hall, New Jersey. pp.13–32.
2. Brooks, R.R. and Radford, C.C. 1978. An evaluation of background and anomalous copper and zinc concentrations in the “ copper plant”Polycarpaea spirostylisand other Australian species of the genus.Proc. Australas. Inst. Min. Metall., No. 268, pp.33–37.
3. Brooks, R.R. 1983.Biological Methods of Prospecting for Minerals. Wiley, New York, 350pp.
4. Chaffee, M.A. and Hessin, T.D. 1971. An evolution of some geochemical sampling in the search for concealed porphyry copper- molybdenum deposits on pediments in Southern Arizona, U.S.A., in Geochemical Exploration, Boyle, R.W. (ed)., sp. vol. No.11,Canadian Inst. of Mining and Metallurgy, pp.401–409.
5. Cole, M.M. 1971. The importance of environment in bio-geographical/ geobotanical and biogeochemical investigations. In Geochemical Exploration, Boyle, R.W. (ed)., sp. vol. No.11,Canadian Inst. of Mining and Metallurgy, pp.414–425.