Source

Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report: Increases in Drug and Opioid Overdose Deaths - United States, 2000-2014. 2016.https://www.incb.org/documents/Narcotic-Drugs/Technical-Publications/2014/Narcotic_Drugs_Report_2014.pd. Accessed June 2018.

https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6450a3.htm