1. Currie, L.A. “Detection and quantitation in X-ray Fluorescence,” in X-ray Fluorescence Analysis of Environmental Samples; Dzubay, T.G., Ed.; Ann Arbor, Science Publishers: Ann Arbor, MI, 1977; p. 295.
2. Taylor, S.R.; McLennan, S.M. The Continental Crust: Its Composition and Evolution; Blackwell Scientific: Oxford, 1985; p. 46.
3. Kennish, M.J. Practical Handbook of Marine Science; Boca Raton, FLA, 1994; pp. 116–117.