1. Abbt-Braun, G., 1996. Refraktäre organische Säuren (Huminstoffe) in aquatischen Systemen—Vorkommen, Reaktionen und Charakterisierung. Wasser Kalender 1997, Erich Schmidt Verlag Berlin, pp. 112–141.
2. Isolation of organic substances from aquatic and terrestrial systems—comparison of some methods;Abbt-Braun;Z. Wasser-Abwasser-Forsch.,1991
3. Aiken, G.R., McKnight, D.M., Wershaw, R.L., MacCathy, P. (Eds.), 1985. Humic Substances in Soil, Sediment and Water. Wiley, New York.
4. Broeker, W.S., 1985. How to Build a Habitable Planet. Eldigio Press, New York.
5. Christman, R.F., Gjessing, E.T. (Eds.), 1983. Aquatic and Terrestrial Humic Materials. Ann Arbor Science, MI.