- DEA Statement: https://www.dea.gov/pr/speeches-testimony/2018t/050818t.pdf
- UNODC 2018 World Drug Report: https://www.unodc.org/wdr2018/en/topics.html
- Centers for Disease Control and Prevention: https://www.cdc.gov/drugoverdose/opioids/index.html
- DEA Fentanyl FAQs: https://www.dea.gov/factsheets/fentanyl
- National Drug Control Strategy: https://2017-2021.state.gov/national-drug-control-strategy/