1. A liberal drift The Economist 2012 http://www.economist.com/news/united-states/21565972-local-votes-suggest-more-tolerant-countrybut-not-more-left-wing-one-liberal-drift
2. Harkinson , J. Will your state be next to legalize pot? Mother Jones 2014 http://www.motherjones.com/politics/2014/02/pot-marijuana-legalization-map-states
3. Amendment 64 Implementation Task Force Task force report on the implementation of Amendment 64: regulation of marijuana in Colorado http://www.colorado.gov/cms/forms/dor-tax/A64TaskForceFinalReport.pdf 2013
4. Overview of Amendment 64 Campaign to Regulate Marijuana Like Alcohol website http://www.regulatemarijuana.org/about. 2014
5. Colorado Department of Revenue Marijuana Enforcement Division 1CCR 212-2: permanent rules related to the Colorado retail marijuana code http://www.colorado.gov/cs/Satellite?c= Document_C&childpagename=Rev-MMJ%2FDocument_C%2FCBONAddLinkView&cid=1251646149281&pagename=CBONWrapper 2013