1. Acar JF (1980) The disc susceptibility test. In: Lorian V (ed) Antibiotics in Laboratory Medicine. Williams & Wilkens, London, pp 24–54
2. Adams J, Kinney T, Thompson S, Rubin L, Helling RB (1979) Frequency dependent selection for plasmid containing cells of Eschrichia coli. Genetics 91:627–637
3. Alexander M (1977) Introduction to Soil Microbiology John Wiley, New York, pp
4. Bachofen R, Schenk A (1998) Quorum, sensing autoinducers: do they play a role in natural microbial habitats? Microbiol Res 153:61–63
5. Brian PW (1957) The ecological significance of antibiotic production. Symp Soc. Gen Microbiol 7:168–188