1. Drake's Island of Thieves: ethnological sleuthing;Lessa,1975
2. The story of pan chewing in India;Gowda;Botanical Mus Leaflets (Harvard University),1951
3. Betel chewing traditions in South-East Asia;Rooney,1993
4. An overview of drugs in Oceania;Marshall,1987
5. The golden Chersonese and the way thither;Bird,1883