Allen ON (1953) Experiments in Soil Bacteriology. Burgess publication company, Minneapology Minnesota, U.S.A. Pp: 69-70.

Aquilanti L, Favilli F, Cleminti F (2004) Comparison of different strategies for isolation and preliminary identification of Azotobacter from soil samples. Soil Biology and Biochemistry 36: 1475-1483.

Ayala S, Rao EVSP (2002) Perspective of soil fertility management with a focus on fertilizer use for crop productivity. Current Science 82: 797-807.

Brenner DJ, Krieg NR, Staley JT (2005) Bergy’s Manual of Systematic Bacteriology. In: The Proteobacteria part B, The Gammaproteobacteria Second Edition, Springer Science and Business Media, Inc., New York, USA.

Cappuccino JC, Sherman N (1992) Microbiology: A Laboratory Manual (3rded), Benjamin cummings Publishing Company, New York, Pp. 125-179.

Gibbs BM, Shapton DA (1968) Identification methods for microbiologists. Society of Applied Microbiology, No.2 pp.xi+212 pp.

Hitchins VM, Sadoff HL (1973) Morphogenesis of cysts in Azotobacter vinelandii. Journal of Bacteriology 104:492-498.

Jacobson E (2000) Pathogenic Roles for Fungal Melanins. Clinical Microbiology Reviews 13 : 708 - 717.

Jenifer AMR, Reena A, Aysha OS, Valli S, Nirmala P, Vinothkumar P (2013) Isolation of siderophore producing bacteria from rhizosphere soil and their antagonistic activity against selected fungal plant pathogens. International Journal of Current Microbiology and Applied Science 2 : 59-65.

Jiménez  DJ, Montaña JS,  Martínez  MM (2011) Characterization of free Nitrogen Fixing Bacteria of the genus Azotobacter in Organic Vegetable Grown Colombian Soils. Brazilian Journal of Microbiology 42: DOI: 10.1590/S1517-83822011000300003.

Joshi KK, Kumar V, Dubey RC, Maheshwari DK (2006) Effect of chemical fertilizer adaptive variants, Pseudomonas aeruginosa GRC2 and Azotobacter chroococcum AC1 on Macrophomina phaseolina causing charcoal rot of Brassica juncea. Korean Journal of Environmental Agriculture 1: 228-235. DOI: 10.5338/KJEA.2006.25.3.228.

Juarez B, Martinez-Toledo MV, Gonzalez-Lopez J (2005) Growth of Azotobacter chroococcum in chemically defined media containing p-hydroxybenzoic                 acid and protocatechuic acid. Chemosphere 59 :1361-1365.

Komagata K, Iino T, Yamada Y (2014) The Family Acetobacteraceae. Rosenberg E, DeLong EF, Lory S, Stackebrandt E, Thompson F (Eds.) The Prokaryotes. Springer, Berlin, Heidelberg, Pp. 3-78. https://doi.org/10.1007/978-3-642-30197-1_396.

Kumar A, Singh R, Giri DD, Singh PK, Pandey KD (2014) Effect of Azotobacter chroococcum CL13 inoculation on growth and curcumin content of Turmeric (Curcuma longa L.). International Journal of Current Microbiology and Applied Science 3 : 275-283.

Moreno J, Vargas-Garcla C, Lopez MJ, Sanchez-serrano G (1999) Growth and exopolysaccharide production by Azotobacter vinelandii in media containing phenolic acids. Journal of Applied Microbiology 86: 430-445.

Murumkar DR, Borkar SG, Chimote VP (2012) Diversity of cell morphology, nitrogenase activity and DNA profile of Azotobacter isolates from soils of Maharastra. Bioinfolet 9 : 851-858.

Narula N, Remus R, Deubel A,  Granse A,  Dudeja SS,  Behl RK,  Merbach W (2007) Comparison of the effectiveness of wheat roots colonization by Azotobacter chroococcum and Pantoea agglomerans using serological techniques. Plant, Soil and Environment 53: 167–176.

Orville W, Marilyn G, Neumann, Socolofsky MD (1961) Development and germination of the Azotobacter cyst. The Journal of Biophysical and Biochemical Cytology10: 555-565.             

Page WJ, Shivprasad S (1991) Azotobacter salinestris sp. nov., a Sodium-Dependent, Microaerophilic, and Aeroadaptive Nitrogen-Fixing Bacterium. International Journal of Systematic Bacteriology 41: 369-376. doi: 10.1099/00207713-41-3-369.

Socolofsky MD, Orville W (1962) Resistance of the Azotobacter cyst.  Journal of Bacteriology 84:119-124.

Winogradsky SN (1949) Microbiologie du soil problems et methods (e.f.). The Azotobacteraceae. Bacteriological Review 18: 199.

Wu FJ, Moreno J, Vela GR (2006) Growth of Azotobacter vinelandii. Applied and Environmental Microbiology 58: 78-82.