Generating Functions for Some Classes of Univalent Functions
Zdzisław Lewandowski, Sanford A. Miller, Eligiusz J. Złotkiewicz · Proceedings of the American Mathematical Society · 1976
Let $P(z) = {e^{i\beta }} + {p_1}z + {p_2}{z^2} + \cdots$ be regular in the unit disc $\Delta$ with $|\beta | 0$ implies $\operatorname {Re} p(z) > 0$. This result is then used to generate subclasses of starlike, spirallike and close-to-convex functions.