1. Burkholder, W. H., and Starr, M. P., Phytopath., 38, 494 (1948).
2. Stapp, C., “Handbuch der Pflanzen-krankheiten”, Band 2 (Paul Parey, Berlin and Hamburg, 1956).
3. Bergey's “Manual of Determinative Bacteriology”, 7th edit., edit. by Breed, R. S., Murray, E. G. D., and Smith, N. R. (Baillière, Tindall and Cox, London, 1957).
4. Wernham, C. C., Phytopath., 38, 283 (1948).