1. Brakke, Estes & Schuster, Phytopathology 55: 79, 1965.
2. Brandes, Phillipe & Thornberry, Phytopath. Z. 50: 181, 1964.
3. Canova, Phytopath. Mediterranea 5: 53, 1966.
4. Estes & Brakke, Virology 28: 772, 1966.
5. Gumpf, Ph.D. Thesis, University of Nebraska, Lincoln, 1970.
6. Gumpf, Virology 43: 588, 1971.
7. Inouye, Ber. Ohara Inst. landw. Biol. 15: A7, 1969.
8. Koehler, Bever & Bonnett, Bull. Ill. agric. Exp. Stn 556: 567, 1952.
9. Linford & McKinney, Pl. Dis. Reptr 38: 711, 1954.
10. McKinney, J. agric. Res. 23: 771, 1923.
11. McKinney, Science, N.Y. 73: 650, 1931.
12. McKinney, Circ. U.S. Dep. Agric. 442, 22 pp., 1937.
13. McKinney, J. Wash. Acad. Sci, 34: 322, 1944.
14. McKinney, Phytopathology 38: 1003, 1948.
15. McKinney, Eckerson & Webb, J. agric. Res. 26: 605, 1923.
16. McKinney, Paden & Koehler, Pl. Dis. Reptr 41: 256, 1957.
17. McKinney, Silber & Greeley, Phytopathology 55: 1043, 1965.
18. Paulsen, Phytopathology 60: 1307, 1970.
19. Peterson, Virology 42: 304, 1970.
20. Pring & Gumpf, Pl. Dis. Reptr 54: 550, 1970.
21. Rao, Phytopathology 58: 1516, 1968.
22. Rao & Brakke, Phytopathology 59: 581, 1969.
23. Rao & Brakke, Phytopathology 60: 714, 1970.
24. Saito, Takanashi, Iwata & Okamoto, Bull. natn. Inst. agric. Sci., Tokyo Ser. C 17: 1, 1964a.
25. Saito, Takanashi & Iwata, Bull. natn. Inst. agric. Sci., Tokyo Ser. C 17: 23, 1964b.
26. Saito, Takanashi, Iwata & Okamoto, Bull. natn. Inst. agric. Sci., Tokyo Ser. C 17: 41, 1964c.
27. Saito, Takanashi, Iwata & Okamoto, Bull. natn. Inst. agric. Sci., Tokyo Ser. C 17: 61, 1964d.
28. Slykhuis, Phytopathology 60: 319, 1970.
29. Tsuchizaki, Hibino & Saito, Ann. phytopath. Soc. Japan 36 : 187, 1970.