1. Faculty of pain medicine Royal College of Anaesthetists. Core standards for pain management services in the UK. http://www.rcoa.ac.uk/document-store/core-standards-pain-management-services-the-uk

2. Welsh Assembly Government. Service development and commissioning directives: Chronic non-malignant pain http://gov.wales.topics/health/publications/health/strategies/pain/?lang=en.

3. Rowbotham D J and Collett B J. Chapter 12: Guidelines for the provision of anaesthetic services. Anaesthetic services for chronic pain management. 2014.http://rcoa.ac.uk/gpas2014.

4. All Wales Medicines Strategy Group. Persistent Pain Resources. October 2016.http://www.awmsg.org/docs/awmsg/medman/Persistent%20Pain%20Resources%20-%20Medicines%20Used%20in%20Persistent%20Pain.pdf

5. All Wales Medicines Strategy Group. National Prescribing Indicators 2016-2017. February 2016.http://www.awmsg.org/docs/awmsg/medman/National%20Prescribing%20Indicators%202016-2017.pdf

6. Scottish Intercollegiate Guidelines Network. SIGN 136. Management of chronic pain. A national clinical guideline. http://sign.ac.uk/guidelines/fulltext/136/index.html