Bibliography
www.en.wikipedia.org/wiki/Lung
http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=2406
www.betterhealth.vic.gov.au/bhcv2/.../Respiratory_system
ww.library.thinkquest.org/5777/resp1.htm
www.kidshealth.org/kid/watch/house/smoking.html
http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=2406
www.betterhealth.vic.gov.au/bhcv2/.../Respiratory_system
ww.library.thinkquest.org/5777/resp1.htm
www.kidshealth.org/kid/watch/house/smoking.html