1. A. P. Roelfs, “Estimated Losses Caused by Rust in Small Grain Cereals in the United States—1918—76,” Miscellaneous Publication No. 1363, U. S. Dept, of Agric., 1978.
2. A. P. Roelfs, D. H. Casper and D. L. Long, Plant Dis. Reptr. 63, 701 (1979).
3. A. P. Roelfs, Plant Disease, 66, 177 (1982).
4. J. B. Rowell, Ann. Rev. Phytopathol. 6, 243 (1968).
5. J. B. Rowell, J. Environ, Qual, 1, 216 (1972).