Sources
- Anderson, E. F. (2001). The Cactus Family. Portland, OR, USA: Timber Press.
- Benson, L. H. (1982). The Cacti of the United States and Canada. Stanford, CA, USA: Stanford University Press.
- Donkin, R. (1977). "Spanish Red: An Ethnogeographical Study of Cochineal and the Opuntia Cactus". Transactions of the American Philosophical Society 67: 1–77. doi:10.2307/1006195.
- Griffith, M. P. (2004). "The Origins of an Important Cactus Crop, Opuntia ficus-indica (Cactaceae): New Molecular Evidence" (pdf). American Journal of Botany 91 (11): 1915–1921. http://www.amjbot.org/content/91/11/1915.full.pdf.
- Kiesling, R. (1999). "Origen, Domesticación y Distribución de Opuntia ficus-indica (Cactaceae)". Journal of the Professional Association for Cactus Development 3: 50–60.
Read more about this topic: Opuntia Ficus-indica
Famous quotes containing the word sources:
“My profession brought me in contact with various minds. Earnest, serious discussion on the condition of woman enlivened my business room; failures of banks, no dividends from railroads, defalcations of all kinds, public and private, widows and orphans and unmarried women beggared by the dishonesty, or the mismanagement of men, were fruitful sources of conversation; confidence in man as a protector was evidently losing ground, and women were beginning to see that they must protect themselves.”
—Harriot K. Hunt (1805–1875)
“The American grips himself, at the very sources of his consciousness, in a grip of care: and then, to so much of the rest of life, is indifferent. Whereas, the European hasn’t got so much care in him, so he cares much more for life and living.”
—D.H. (David Herbert)
“I count him a great man who inhabits a higher sphere of thought, into which other men rise with labor and difficulty; he has but to open his eyes to see things in a true light, and in large relations; whilst they must make painful corrections, and keep a vigilant eye on many sources of error.”
—Ralph Waldo Emerson (1803–1882)