http://www.withdrawal.net/learn/dextromethorphan/
http://www.eaglevillehospital.org/PDFs/DXM.pdf
http://www.drugfree.org/drug-guide/dxm/
http://drug-effects.us/dxm-effects-short-long-term/
http://www.bluelight.org/vb/threads/367073-DXM-Subthread-Long-term-DXM-Effects-amp-Addiction