Denote by the class of functions of the form: (1) that are harmonic univalent and sense-preserving in the unit disc for which and by the subclass of for which .
Let: (2) , , . Denote by and the subclasses of consisting of functions that map onto starlike and convex domains, respectively. Let and be the subclasses of and , respectively, whose coefficients take the form: (3) , ; , , .
In the present paper mentioned above classes of harmonic functions are considered. The author proves among others: Theorem 1. If of the form (1-2) satisfies , then . Corollary 1. If of the form (1-2) satisfies , then . Theorem 2. For of the form (1), (3), if and only if . Theorem 3. For of the form (1), (3), if and only if .