1. World Health Organization20162018-03-08Global report on diabetes
http://apps.who.int/iris/bitstream/10665/204871/1/9789241565257_eng.pdf
2. National Diabetes AuditNHS Digital2018-03-08National diabetes audit 2012-2013
https://files.digital.nhs.uk/publicationimport/pub14xxx/pub14970/nati-diab-audi-12-13-care-proc-rep.pdf and the archived link is http://www.webcitation.org/74pbHGmRe
3. The significance of compliance and persistence in the treatment of diabetes, hypertension and dyslipidaemia: a review
4. Retrospective Analysis of Long-Term Adherence to and Persistence with DPP-4 Inhibitors in US Adults with Type 2 Diabetes Mellitus