Ryan, George (2017) Novel psychoactive substances: synthetic cannabinoids - best practice treatment approaches. London: SMMGP.

Ford, Chris and Halliday, Kate and Lawson, Euan and Browne, Elsa (2011) Guidance for the use of substitute prescribing in the treatment of opioid dependence in primary care. London: RCGP Substance Misuse Unit; RCGP Sex, Drugs and HIV Group; Substance Misuse Management in General Practice; The Alliance.