AFIFY, A. E.-M. M., E. A. SHALABY, and H. S. EL-BELTAGI. “Antioxidant Activity of Aqueous Extracts of Different Caffeine Products”. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Vol. 39, no. 2, Nov. 2011, pp. 117-23, doi:10.15835/nbha3926254.