Olatunji, Sunday Oluwafemi, and Hemen Dutta. 2019. “Fekete-Szegö Problem for Certain Classes of Analytic Functions Associated With Petal Type Domain and Modified Sigmoid Function”. Science & Technology Asia 24 (4):144-52. https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/185469.