1. Drug and Alcohol Involvement in Four Types of Fatal Crashes*
2. http://www.drugabuse.gov/publications/drugfacts/nationwide-trends(accessed December 2016).
3. BerningA ComptonR WochingerK.Results of the 2013‐14 national roadside survey of alcohol and drug use by drivers: traffic safety facts: research note.Washington DC:National Highway Traffic Safety Administration: US Department of Transportation 2015; Report No.: DOT HS 812 118.
4. Changing Patterns of Drug and Alcohol Use in Fatally Injured Drivers in Washington State
5. U.S. Department of Transportation: National Highway Traffic Safety Administration.Drug Evaluation and Classification Training Program; The Drug Recognition Expert School – student manual. January 2007 ed.Washington DC:U. S. Department of Transportation: National Traffic Safety Administration 2007.