Sudibyo, Sudibyo, Lilis Hermida, and Puwala Ardhana Reswari. 2021. “Optimization of Electrometal - Electrowinning Cobalt Process from the Slag of Nickel Pig Iron (NPI)”. Journal of Materials Science and Applied Energy 10 (2), 49 - 57. https://ph01.tci-thaijo.org/index.php/jmsae_ceae/article/view/242741.