Stas, Jamal, Ajaj Dahdouh, and Omar Al-Chayah. 2007. “Recovery of Vanadium, Nickel and Molybdenum from Fly Ash of Heavy Oil-Fired Electrical Power Station”. Periodica Polytechnica Chemical Engineering 51 (2):67-70. https://doi.org/10.3311/pp.ch.2007-2.11.