1. Studies on the aerobic non-symbiotic nitro. gen-fixing bacteria, other than Azotobacter, in Egyptian soils;Abd-El-Malek;Zbl. Bakt. II,1979
2. Standard Methods for the Examination of Water, Sewage, and Industrial Wastes,1955
3. Bergey's Manual of Determinative Bacteriology,1974
4. Nitrogen fixation by a species of Pullularia;Brown;Nature (Lond.),1957
5. Application of the acetylene-ethylene assay for measurement of nitrogen fixation;Hardy;Soil Biol. Biochem.,1973