Dragons in Little Paradise (article)
Liua’ana, Ben Featuna’i. “Dragons in Little Paradise: Chinese (Mis-)Fortunes in Samoa, 1900-1950.” Journal of Pacific History 32:1 (1997), 29-48. [Narrates the drug use among Chinese indentured servants that emigrated to Samoa.]
An brief history of kava root, with a few references, can be found here.