1. Hess,D., in H.Bothe and A. Trebst (eds.), Biology of Inorganic Nitrogen and Sulfur, pp. 287–298. Berlin-Heidelberg-New York, Springer 1981.
2. Hess, D., in P.H. Graham, J. Halliday, P.J.Dart (eds.), Proc. Workshop Biol.Nitrogen Fixation Technology for Tropical Agriculture. CIAT Publication, Cali in press (1981).
3. Hess, D., H.Schätzle and K.Dressler: Experientia in Press (1981).
4. Hess, D., and S. Kiefer: Z. Pflanzenphysiol. 101, 15–24 (1981).
5. Hess,D., T. Mertens, and H. Pudil: in preparation