4.0 truetrue UNODC (2008) "2.1 Origins: The development of the opium problem in China" in World Drug Report 2008, p. 175 Ebrey, Patricia Buckley (2010)...
DescriptionOpium imports into China 1650-1880 EN.svg English: Opium imports into China 1650-1850 Date 24 March 2014 Source Own work from United Nations...