how to properly cite a website

SORCE#1
Hughes T what is asthma worldconstruction.com retrieving November 8,2011 from


http://www.wordconstructions.com/articles/health/asthma.html




SORCE #2

STÖPPLER M asthma emedicinehealth.com retrieving on November 8,2011 from 

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

SORCE#3

whats asthma nhlbi.nih.gov rertieving on november 8,2011 from

http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/