Olatunji, S. O., and H. Dutta. “Fekete-Szegö Problem for Certain Classes of Analytic Functions Associated With Petal Type Domain and Modified Sigmoid Function”. Science & Technology Asia, vol. 24, no. 4, Nov. 2019, pp. 144-52, https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/185469.