1. Le Khat. Toxique du Territoire des A fars et des Issas;Absieh,1973
2. What science has to say concerning Kat: It is not a narcotic. … but!!;Abu,1982
3. East African Crops;Acland,1971
4. Report of the Qat Commission of Inquiry;Aden,1958
5. Chemical pharmacology of Catha edulis;Alles;Journal of Medicinal and Pharmaceutical Chemistry,1961