As successful as the theory of integration with respect to countably additive vector measures has been in various branches of mathematics, such as mathematical physics, functional analysis and operator theory, for example, it is also known that there are fundamental problems which cannot be treated in this way. Nevertheless, these problems still seem to require for their solution "some sort of integration process" that Kluvánek pursued to the end of his career. Some of his galaxy of ideas about integration appeared in his book Integration Structures.