1. United Nations Office on Drugs and Crime (UNODC) (2015) Early Warning Advisory on new psychoactive substances. What are NPS?
https://www.unodc.org/LSS/Page/NPS
. Accessed 20 May 2017
2. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) (2016) European drug report. Trends and developments.
http://www.emcdda.europa.eu/system/files/publications/2637/TDAT16001ENN.pdf
. Accessed 20 May 2017
3. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) (2015) New psychoactive substances in Europe. An update of the EU Early Warning System
http://www.emcdda.europa.eu/system/files/publications/65/TD0415135ENN.pdf
. Accessed 20 May 2017
4. Mounteney J, Giraudon I, Denissov G, Griffiths P (2015) Fentanyls: are we missing the signs? Highly potent and on the rise in Europe. Int J Drug Policy 26:626–631
5. Papoutsis I, Nikolaou P, Athanaselis S, Vardakou I, Spiliopoulou C, Stefanidou M (2016) Fentanyl-related cases. The situation in Greece. Eur J Forensic Sci 3:16–20