1. D. G. Brookins,Eh-pH Diagrams for Geochemistry, Springer-Verlag, Berlin, 97–101 (1988).
2. S. Uchida, H. Takeda, K. Tagami, T. Takahashi, N. Ogiu, T. Aono,Elemental Concentrations in Japanese Rivers 2002–2006, ISBN 978-4-938987-42-8, National Institute of Radiological Sciences, Chiba, 182 (2007), [part of the text is in English].