1. Anke,T. (1989). In: Bioactive metabolites from microorganisms. Progress in industrial microbiology - vol.27, ed. M.E. Bushell and U. Gr�fe, pp 51?66. Elsevier. London
2. Clarke, D.S. (1962). Can. J. Microbiol. 8: 133?136
3. Cox, P.W., Thomas, C.R. (1992). Biotechnol. Bioeng. 39: 945?952
4. Fachet, J., Abel, G., Jusupova, S., Imre, S., Katona, E., Erdei, J., Sz�ll�si, J., Chihara, G. (1989). Int. J. Immunother. 4:167?176
5. Furue, H. (1987). Drugs of today. 23(6): 335?346