Galib Atshan, Waggas, and Salwa Kalf Kazim. “Coefficient Estimates for Some Subclasses of Bi-Univalent Functions Related to M-Fold Symmetry”. Journal of Al-Qadisiyah for Computer Science and Mathematics, vol. 11, no. 2, Aug. 2019, pp. math 81-86, doi:10.29304/jqcm.2019.11.2.550.