 The "Engelking-Karlowicz theorem" is a statement about the existence of a family of functions from formula_1 to formula_2 with topological and set-theoretical applications.In addition to research papers authored just by himself, he also published jointly with Kazimierz Kuratowski, Roman Sikorski, Aleksander Pełczyński and others.He has published about 60 scientific works reviewed by MathSciNet and Zentralblatt.