http://emedicine.medscape.com/article/1833084-overview#a15 http://emedicine.medscape.com/article/1833084-overview#a2 http://emedicine.medscape.com/article/1833084-overview#a2 http://emedicine.medscape.com/article/1833084-overview#a15 http://emedicine.medscape.com/article/1833084-overview