Kurbanova, A., N. Akhmetov, A. Yeshmuratov, R. Zulkharnay, Y. Sugurbekov, G. Demeuova, M. Baisariyev, and G. Sugurbekova. “Removal of Nickel and Vanadium from Crude Oil by Using Solvent Extraction and Electrochemical Process”. Physical Sciences and Technology, vol. 4, no. 1, June 2018, pp. 74-80, doi:10.26577/phst-2017-1-127.