1. Aellen P (1967) Amaranthaceae. Illustr Flora Mitteleuropa, Hegi III: 461 –1532
2. Agogino GA (1957) Pigweed seeds dated oldest US food grain. Science Newsl Washingt 72: 345
3. Anonymous (1984) Amaranth, modern prospects for an ancient crop. Natl Acad Res Counc Natl Acad Press, Washington
4. Beadle GW (1972) The mystery of maize. Field Mus Nat Hist Bull 43: 1–11
5. Beadle GW (1977) The origin of Zea mays. In: Reed (ed) Origins of agriculture. Mouton, The Hague, pp 615–635