1. Humic Substances in the Environment;Schnitzer,1972
2. Humic Substances in Soil Sediment and Water;Aiken,1985
3. Humic Substances and Their Role in Environment;Frimmel,1988
4. Humic Substances in Soil Sediment and Water: in Search of Structure;Hayes,1989
5. Refractory Organic Substances in the Environment;Frimmel,2002