http://www.merck.com/!!s9OfD17kBs9OwL2Wwl/disease/preventable/hepb/
Facts on hepatitis B (symptoms, statistics, spread, and prevention).

http://www.geocities.com/Paris/4664/introli.html
An explanation of lactose intolerance in laypersons' terminology with a few links to other sources of information about this condition.