1. Online sales of new psychoactive substances/legal highs: summary of results from the 2011 multilingual snapshots,2011
2. Legal Highs on the Internet;Hillebrand;Subst. Use Misuse,2010
3. Control of a chemical precursor used in the illicit manufacture of fentanyl as a list I chemical;Final rule, Fed Regist,2008
4. United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychoactive Substances, United Nations, Vienna,1998
5. US Drug Enforcement Administration, Department of Justice, General information regarding the combat methamphetamine epidemic act of 2005 [Title VII of Public Law 109–177], (2006).