3. Gollwitzer, P. M., K. Fujita, and G. Oettingen. 2004. Planning and the implementation of goals. In Handbook of self-regulation: Research, theory, and applications, R. F. Baumeister and K. D. Vohs, Eds. New York: Guilford Press.

4. Jeffery, Robert W. and Jennifer Utter. 2003. The Changing Environment and Population Obesity in the United States. Obesity Research 11, DOI: 10.1038/ oby.2003.221.

5. Johnson, H. D., D. Sholoscky, K. L. Gabello, R. V. Ragni, and N. M. Ogonosky. 2003. Gender differences in handwashing behavior associated with visual behavior prompts. Perceptual and Motor Skills 97: 805–810.

6. Norman, Donald. 1990. The Design of Everyday Things. New York: Doubleday Business. Originally published as The Psychology of Everyday Things. 1988. New York: Basic Books.