References
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Isolation of Nitrogen fixing Rhizobium bacteria.
http://www.nexusresearchgroup.com/microbiology/rhiziso.htm.
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Urban, J. E., and F. B. Dazzo. 1982. Succinate-induced morphology of Rhizobium trifolii 0403 resembles that of bacteroids in clover nodules. Appl. Environ. Microbiol. 44:219226.