M. Kumar, A. Afzal, and R. M K, “Investigation of physicochemical and tribological properties of TiO2 nano-lubricant oil of different concentrations”, Finnish J. Trib., vol. 35, no. 3, pp. 6–15, Dec. 2017, Accessed: Mar. 25, 2026. [Online]. Available: https://journal.fi/tribologia/article/view/60703