1. Use of chrome azurol S reagents to evaluate siderophore production by rhizosphere bacteria;Alexander;Biol. Fertil. Soils,1991
2. Baddeley, J.A., Jones, S., Topp, C.F.E., Watson, C.A., Helming, J., Stoddard, F.L. (2014) Biological nitrogen fixation (BNF) by legume crops in Europe. In: Legume Futures Report 1.5. Legume-supported cropping systems for Europe.
3. R factor transfer in Rhizobium leguminosarum;Beringer;J. Gen. Microbiol.,1974
4. Melanin production by Rhizobium strains;Cubo;Appl. Environ. Microbiol.,1988
5. Sustainable crop nutrition: constraints and opportunities;Denison,2005