Loewner-type approximations for convex functions R. J. Libera; E. J. Złotkiewicz — 1976 Colloquium Mathematicae
Mapping properties of a class of univalent functions with pre-assigned zero and pole Z. A. Lewandowski; R. J. Libera; E. J. Zlotkiewicz — 1983 Annales Polonici Mathematici