1. What is policy convergence and what causes it?;Bennett;British Journal of Political Science,1991
2. Birdwell, J., Chapman, J., & Singleton, N. (2011). Taking drugs seriously: A demos and UK drug policy commission report on legal highs. Retrieved from: http://www.ukdpc.org.uk.
3. The New Zealand ‘psycho’ psychoactive substances legislation;Brown,2015
4. A critical evaluation of the European drug strategy: Has it brought added value to drug policy making at the national level?;Chatwin;International Journal of Drug Policy,2013
5. Drug policy harmonization and the European Union;Chatwin,2011