... paper give important information on the geometric prop-erties of functions satisfying differential subordination conditions involving higher-orderderivatives.6 Journal of Inequalities and Applicationsthenfqzλp; ... Analysis, Conference Proceedings and Lecture Notes in Analysis, I, pp. 157–169, International Press, Tianjin, China, 1994.15 W. Janowski, “Some extremal problems for certain families of analytic ... multivalent functions, see, for example, 1–10. Recently, by the use of the well-known Jack’s lemma 11, 12, Irmak andCho 5 obtained interesting results for certain classes of functions defined...