Srinivasan, V., Rahimah Zakaria, Zahiruddin Othman, and Amnon Brzezinski. 2012. “Melatonin, Insomnia and the Use of Melatonergic Drugs”. Journal of Endocrinology and Reproduction 16 (1):15-24. https://informaticsjournals.com/index.php/jer/article/view/1951.