1. Andrews PWS (1949) Manufacturing business. Macmillan, London
2. Bennett T (1988) The British experience with heroin regulation. Law Contemp Probl 51:299–314
3. Brownstein HH (1996) The rise and fall of a violent crime wave – crack cocaine and the social construction of a crime problem. Harrow ‖ Heston, Guilderland
4. Caulkins JP (2005) Price and purity analysis for illicit drug: data and conceptual issues. Heinz Research. Paper 25. http://repository.cmu.edu/heinzworks/25. Accessed 25 Oct 2011
5. Caulkins JP, Reuter P (1998) What price data tell us about drug markets. J Drug Issues 28:593–612