1. Vasil, I. K. Plant tissue culture and crop improvement—fact fancy. Newsletter IAPTC 26: 2–10; 1978.
2. Nitsch, J. P. Haploid plants from pollen. Z. Pflanzenzuchtg. 67: 3–18; 1972.
3. Emsweller, S. L. Science in farming. Yearbook of agriculture. Washington, D.C.: Bureau of Plant Industry, USDA; 1943-1947: 80.
4. Bamford, R.; Winkler, R. B. A spontaneous tetraploid snapdragon. J. Hered. 32: 218: 1941.
5. Hughes, K. W.; Bell, S. L.; Caponetti, J. D. Anther-derived haploids of the African violet. Can J. Bot. 53: 1442–1444; 1975.