1. Björling & Nilsson, Socker 21: 1, 1966.
2. Costa, Duffus & Bardin, J. Am. Soc. Sug. Beet Technol. 10: 371, 1959.
3. Duffus, Phytopathology 50: 389, 1960.
4. Duffus, Phytopathology 51: 605, 1961.
5. Duffus, Phytopathology 54: 736, 1964.
6. Duffus, Phytopathology 59: 1668, 1969.
7. Duffus & Gold, Virology 27: 388, 1965.
8. Duffus & Gold, Virology 37: 150, 1969.
9. Duffus & Russell, Phytopathology 60: 1199, 1970.
10. Esau & Hoefert, J. Ultrastruct. Res. 40: 556, 1972a.
11. Esau & Hoefert, Virology 48: 724, 1972b.
12. Gold & Duffus, Virology 31: 308, 1967.
13. Ruppel, Phytopathology 58: 256, 1968.
14. Russell, Ann. appl. Biol. 46: 393, 1958.
15. Russell, Ann. appl. Biol. 52: 405, 1963.
16. Russell, Ann. appl. Biol. 55: 245, 1965.
17. Smith, Duffus & Gold, Phytopathology 56: 902, 1966.
18. Sugimoto, Murayama & Sanai, Bull. Sugar Beet Res. 8: 1, 1970.
19. Vanderwalle & Roland, Parasitica 7: 14, 1951.
20. Wallis, J. econ. Ent. 60: 904, 1967.