1. United States Drug Enforcement Agency DEA (2022) Facts about Fentanyl.
https://www.dea.gov/resources/facts-about-fentanyl#:~:text=Fentanyl%20is%20a%20Schedule%20II,for%20potential%20misuse%20or%20abuse
2. European Monitoring Centre for Drugs and Drug Addiction EMCDDA (2011, September).
https://www.emcdda.europa.eu/publications/drug-profiles/fentanyl_en#pharmacology
3. National Institute of Drug Abuse NIDA (2016) Drug Facts: What Is Fentanyl?
https://www.drugabuse.gov/publications/drugfacts/fentanyl#ref
4. Predicting Maternal-Fetal Disposition of Fentanyl Following Intravenous and Epidural Administration Using Physiologically Based Pharmacokinetic Modeling
5. Finnegan, L, Connaughton, J., Kron, R. and Emich, J. (1975) Neonatal Abstinence Syndrome: Assessment and Management. Addictive Diseases, 2, 141-158.