Hamzat , J. O., and A. A. Adeyemo. “New Subclasses of Analytic Functions With Respect to Symmetric and Conjugate Points Defined by Extended Salagean Derivative Operator”. International Journal of Mathematical Sciences and Optimization: Theory and Applications, Vol. 2019, no. 2, Feb. 2020, pp. 644 -56, http://ijmso.unilag.edu.ng/article/view/598.