1. Heun M, Schafer-Pregl R, Klawan D, Castagna R, Accerbi M, Borghi B, Salamini F (1997) Site of einkorn wheat domestication identified by DNA fingerprinting. Science 278(80):1312–1314
2. Zohary D, Hopf M (2000) Domestication of plants in the old world. Oxford University Press, Oxford
3. Goethe JWV (2009) The metamorphosis of plants. MIT Press, Cambridge, p 123. (re-print)
4. Gray A (1879) Structural botany: or organography on the basis of morphology. Ivison Blakeman Taylor, New York/Chicago
5. Bateson W (1894) Materials for the study of variation treated with special regard to discontinuity in the origin of species. Macmillan, London