Opium in China.
D002681:China; D049669:History, 16th Century; D049673:History, 20th Century; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D008518:Medicine, East Asian Traditional; D009892:Opium; D019966:Substance-Related Disorders / Q000266:history
D009892:Opium