1. Mineralöl und Raffinerien. Mineralölwirtschaftsverband e. V., Hamburg, March 1985.
2. The Chemistry and Technology of Petroleum, Marcel Dekker Inc., New York 1980.
3. The Concept of Asphaltenes, Symposium on the Chemistry of Asphaltenes, Amer. Chem. Soc., Washington 1972.
4. Molecular Weight and Association of Asphaltenes: a Critical Review