1. "Children with Attention Deficits Concentrate Better After Walk in the Park," Andrea Faber Taylor and Frances E. Kuo, Journal of Attention Disorders, Vol. 12, No. 5, 402-409 (2009) www.lhhl.uiuc.edu.
2. Centers for Disease Control and Prevention. www.cdc.gov/ncbddd/ADHD/index.html
3. Smart Guide to Food Dyes: Buying foods that can help learning. Institute for Agriculture and Trade Policy. www.iatp.org
4. Center for Science in the Public Interest. Campaign to ban food dyes linked to ADHD: www.cspinet.org/fooddyes/
5. “Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder,” Richard Louv, Algonquin Books (2006).