1. Cadman, C. H.: Autotetraploid inheritance in the potato: some new evidence. Il. Genetics44, 33–52 (1942).
2. Cockerham, G.: The reaction of potato varieties to viruses X, A, B and C. Ann. appl. Biol.30, 338 (1943).
3. Gäumann, E.: Pflanzliche Infektionslehre. Basel 1946.
4. Hutton, E. M.: Possible genotypes conditioning virus resistance in the potato and tomato. Austral. Instit. Agr. Res.17, 132–138 (1951).
5. Hutton, E. M. andD. C. Wark: A relationship between immunity and localised reaction to virus X in the potato. Austr. Il. of Sci. Res.5, 237–243 (1952).