1. Humphrey, A. E.; Reilly, P. J.; Biotechnol. Bioeng.7 (1965), 229?243
2. Lien, O.G. Anal. Chem.31 (1959), 1363?1366
3. Lockwood, L. B. Production of Organic Acids by Fermentation, pp. 355?387 in: Peppler, H. J.; Perlman, D. (Eds._ Microbial Technology Vol. I Academic Press, N. Y. 1979
4. Onken, U.; Kiese, S.; Jostmann, Th. Biotechnol. Letters6 (1984), 283?288.
5. Oosterhuis, N.M.G.; Groesbeek, N.M.; Kossen, N.W.F.; Schenk, E.S. Appl. Microbiol. Biotechnol.21 (1985), 42?49