World Health Organization: Division of Mental Health and Prevention of Substance Abuse (1997). Cannabis: a health perspective and research agenda(PDF). p. 11. WHO/MSA/PSA/97.4. Archived from the original(PDF) on 23 December 2014. Retrieved 1 December 2008.
"Joint". Dictionary.reference.com. Archived from the original on 23 April 2011. Retrieved 20 April 2011.
"Roach Clip". lookah.com. Archived from the original on 26 January 2021. Retrieved 10 October 2020.
who.int
whqlibdoc.who.int
World Health Organization: Division of Mental Health and Prevention of Substance Abuse (1997). Cannabis: a health perspective and research agenda(PDF). p. 11. WHO/MSA/PSA/97.4. Archived from the original(PDF) on 23 December 2014. Retrieved 1 December 2008.