Source

Guy GP Jr., Zhang K, Bohm MK, et al. Vital Signs: Changes in Opioid Prescribing in the United States, 2006–2015. MMWR Morb Mortal Wkly Rep 2017;66:697–704. DOI: http://dx.doi.org/10.15585/mmwr.mm6626a4

https://www.cdc.gov/mmwr/volumes/66/wr/mm6626a4.htm