Sonawane, S. A., and M. L. Kulkarni. “Multi-Response Optimization of Wire Electrical Discharge Machining for Titanium Grade-5 by Weighted Principal Component Analysis”. International Journal of Engineering and Technology Innovation, Vol. 8, no. 2, Mar. 2018, pp. 133-45, https://ojs.imeti.org/index.php/IJETI/article/view/666.