1. Stockwell C. Nature's Pharmacy: A History of Plants and Healing, 1st edn. London: Arrow Books, 1989; 57.
2. Lovell RC.Lawsonia inermis (L. alba).In: Plants and the Skin, 1st edn. Oxford: Blackwell Scientific Publications, 1993; 38–141.
3. Poisoning from henna dye and para-phenylenediamine mixtures in children in Khartoum
4. Wern RC. Potter's New Cyclopaedia of Botanical Drugs and Preparations, revised edn. Saffron Walden: CW Daniel, 1988; 143.