1. Substance Abuse and Mental Health Services Administration. The TEDS report: Age of substance use initiation among treatment admissions aged 18 to 30. 2014. http://www.samhsa.gov/data/sites/default/files/WebFiles_TEDS_SR142_AgeatInit_07-10-14/TEDS-SR142-AgeatInit-2014.htm .
2. Central Bureau of Statistics. Survey report on current hard drug users in Nepal. 2013. http://www.moha.gov.np/uploads/documentFiles/drug%20survey_20140202035708.pdf .
3. Dawson DA, Goldstein RB, Chou SP, Ruan WJ, Grant BF. Age at first drink and the first incidence of adult-onset DSM-IV alcohol use disorders. Alcohol Clin Exp Res. 2008;32(12):2149–60.
4. King KM, Chassin L. A prospective study of the effects of age of initiation of alcohol and drug use on young adult substance dependence. J Stud Alcohol Drugs. 2007;68(2):256–65.
5. Substance Abuse and Mental Health Services Administration. Results from the 2012 National Survey on Drug Use and Health: summary of national findings. Rockville: Substance Abuse and Mental Health Services Administration; 2013. http://www.samhsa.gov/data/sites/default/files/NSDUHresults2012/NSDUHresults2012.pdf .