1. Zsolnay A (1996) In: Piccolo A (ed) Humic substances in terrestrial ecosystems. Elsevier, Amsterdam
2. Morel F, Hering JG (1993) Principles and applications of aquatic chemistry. John Wiley & Sons, New York
3. Stevenson FJ (1994) Humus chemistry: genesis, composition, reactions. John Wiley & Sons, New York
4. Senesi N (1990) Anal Chim Acta 232:77–106
5. Clark CD, Jimenez-Morais J, Jones G, Zanardi-Lamardo E, Moore CA, Zika RG (2002) Marine Chem 78:121–135