1. Bains, G. S. (vide
Dodds and Paxman, 1962), Cytogenetical studies in the genus Solanum sect. Tuberarium. Unpub. M.Sc. Degree Dissertation, Univ. Cambridge (1951).
2. Beamish, K. I., The effect of pollen aging on seed development in Solanum. Amer. Potato Jour. 31 (1954): 366 (Abst.).
3. Cipar, M. S., Incompatibility relationships among haploids of Solanum tuberosum subsp. andigena and certain diploid species. Ph.D thesis, University of Wisconsin (1963).
4. 4.Cipar, M. S., S. J. Peloquin and R. W. Hougas, Incompatibility relationships of haploids from Solanum tuberosum subsp. andigena. Amer. Potato Jour. 37 (1960): 345 (Abst.).
5. Carson, G. P. and H. W. Howard, Self-incompatibility in certain diploid potato species. Nature 150 (1942): 290.