Intestinal Flu Causes, Symptoms and its Treatment & Prevention.

CDC : Noroviruses -
 The organism is also known as Norwalk-like viruses or caliciviruses. The disease is also known as stomach flu or viral gastroenteritis. Includes cause, treatment, and prevention.
http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus.htm

eMedicine - Norwalk Virus -
 Article by Michelle A Jaworski, MD.
http://www.emedicine.com/med/topic1648.htm

Food Safety Research Information Office: Norwalk Virus -
Directory of press releases, articles, resources, and factsheets on the disease.
http://www.nal.usda.gov/fsrio/topics/tpnorwalk.htm

Norwalk Virus -
 Factsheet on the disease.
http://www.lambtonhealth.on.ca/communicable/norwalk.asp

Norwalk Virus and Other Caliciviruses -
Scientific and medical information about the virus.
http://gsbs.utmb.edu/microbook/ch065.htm

Norwalk Virus Gastroenteritis: A Different Type of Foodborne Illness, HYG-5569-98 -
Ohio State University Extension fact sheet providing basic information on the subject.
http://ohioline.osu.edu/hyg-fact/5000/5569.html

Norwalk Virus Infection Facts -
Factsheet on the disease with symptoms and prevention.
http://www.astdhpphe.org/infect/norwalk.html

Norwalk Viruses Widespread -
Gastrointestinal infection are often caused by the Norwalk virus or one of its many relatives. These viruses are second only to the common cold in the occurrence of viral illnesses in the US.
http://healthlink.mcw.edu/article/1031002212.html