1. Aiken, W. (1984). Ethical issues in agriculture. In T. Regan (Ed.), Earthbound: New introductory essays in environmental ethics (pp. 274–288). New York: Random House.
2. Alroe, H. F., Vaars, M., & Kristensen, E. S. (2001). Does organic farming face distinctive livestock welfare issues? Journal of Agricultural and Environmental Ethics, 14(3), 275–299.
3. Al-Zahrani, K. H., Elsahfie, I. M., & Muneer, S. E. (2007). Factors affecting adoption of water conservation practices in the household sector in Riyadh City, Saudi Arabia. Retrieved January 18, 2008, from http://www.worldwaterweek.org/stockholmwatersymposium/Abstract_Volume_07/Microsoft%20Word%20-%20Workshop%208.pdf .
4. American Dietetic Association, Dietitians of Canada. (2003). Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets. Journal of the American Dietetic Association. June, Vol.␣103, Number 6, 748–765.
5. American Public Health Association. (2003). Precautionary moratorium on new concentrated animal feed operations. Retrieved October 2008, from http://www.apha.org/advocacy/policy/policysearch/default.htm?id=1243 .