U.S. Pharmacopeia / National Formulary: http://www.usp.org/
British Pharmacopoeia: http://www.newdruginfo.com/pharmacopeia/bp.asp
European Pharmacopeia: http://www.edqm.eu/en/Homepage-628.html
The Japanese Pharmacopoeia: http://www.newdruginfo.com/pharmacopeia/jp.asp
Chinese Pharmacopeia: http://www.newdruginfo.com/pharmacopeia/cp2000.asp
CAS # Search: http://cheman.chemnet.com/dict/zd.html
Organic Reaction: http://www.organic-reaction.com/
Spectral Database for Org. Compds: http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi
Rxlist-The Internet Drug Index: http://www.rxlist.com
Medical Matrix Medical Directory：http://www.medmatrix.org/