http://en.wikipedia.org/wiki/Anxiety

http://www.adaa.org/

http://www.medicinenet.com/anxiety/article.htm

http://www.nlm.nih.gov/medlineplus/anxiety.html

http://www.emedicinehealth.com/anxiety/article_em.htm

http://www.everydayhealth.com/emotional-health/anxiety/index.aspx

http://familydoctor.org/013.xml

http://www.nimh.nih.gov/healthinformation/anxietymenu.cfm

http://kidshealth.org/teen/your_mind/mental_health/anxiety.html

http://www.helpguide.org/mental/anxiety_types_symptoms_treatment.htm