1. Azospirillum II - (Klingmuller, W., ed) Exp. 48, Birkhäuser, Basel.
2. Döbereiner, J. and Day, J.M. (1976). A In Proceedings of the 1st International Symposium on N2 fixation (Newton, W.E. and Nyman, C.J. eds.) pp. 518–537, Washington State Univ. Press.
3. Döbereiner, J. (1983). In Azospirillum II (Klingmuller, W., ed). Exp 48, pp. 9–23, Birkhauser, Basel.
4. Tien, T.M., Gaskins, M.H. and Hubbel, D.H. (1979). Appl. Environ. Microbiol. 37, 1016–1024.
5. Bani, D., Barberio, C., Bazzicalupo, M., Favilli, F., Gallori, E. and Polsinelli, M. (1980). J. Gen. Microbiol. 19, 239–244.