1. Arnold, W. M., Weaver, R. H.: Quick microtechniques for the identification of cultures. I. Indole production. J. Lab. clin. Med.33, 1334–1337 (1948)
2. Brooker, D. C., Lund, M. E., Blazevic, D. J.: Rapid test for lysine decarboxylase activity in Enterobacteriaceae. Appl. Microbiol.26, 622–623 (1973)
3. Bülow, P.: The ONPG test in diagnostic bacteriology. Acta path. microbiol. scand.60, 378–386 (1964)
4. Clarke, P. H., Cowan, S. T.: Biochemical methods for bacteriology. J. gen. Microbiol.6, 187–197 (1952)
5. Cowan, S. T., Steel, K. J.: Manual for the identification of medical bacteria. London: Cambridge University Press 1970