Vladimir Kadets has authored two monographs and more than 100 articles in peer-reviewed journals, mainly in Banach space theory: sequences and series, bases, vector-valued measures and integration, measurable multi-functions and selectors, isomorphic and isometric structures of Banach spaces, operator theory. In 2005 he received the State Award of Ukraine in Science and Technology to honour his research. The present book reflects the author's teaching experience in the field, spanning over more than 20 years.