his research work at the cutting edge of modern science. And if he suddenly opens a new direction in science, then his name immediately gains recognition". In 1974–1987, Samoilenko headed the Chair of Integral and Differential Equations of the Department of Mechanics and Mathematics at the Shevchenko Kyiv State University. These years were marked by especially high scientific activity of the chair. Based on results of the research in the theory of differential equations with delay performed at that time, the monograph of Mitropolskiy, Samoilenko, and D. I. Martynyuk was published. At the same time, Samoilenko, together with his disciple M. O. Perestyuk, published the well-known monograph devoted to the theory of impulsive differential equations. These monographs (especially their English translations) are frequently cited in scientific literature. Since 1987, Samoilenko has headed the Department of Ordinary Differential Equations at the Institute of Mathematics of the Academy of Sciences of the Ukrainian SSR (at present, the Department of Differential Equations and Theory of Oscillations at the Institute of Mathematics of the National Academy of Sciences of Ukraine), and since 1988 he has been the Director of the Institute of Mathematics of the National Academy of Sciences of Ukraine. The beginning of this fruitful creative period was marked by the fundamental monograph devoted to the qualitative theory of invariant manifolds of dynamical systems. This monograph served as a foundation for the construction of the general perturbation theory of invariant tori of nonlinear dynamical systems on a torus. The English version of this monograph is also well known. Three years later, the monograph of Samoilenko (in coauthorship with Mitropol'skii and V. L. Kulyk) was published. In this monograph, in particular, the method of Lyapunov functions was used for the investigation of dichotomies in linear differential systems of the general form. The results of many-year investigations of constructive methods in the theory of boundary-valued problems for ordinary differential equations carried out by Samoilenko together with M. Ronto are presented in monographs. Constructive algorithms for finding solutions of boundary-value problems with different classes of multipoint boundary conditions were developed by Samoilenko, V. M. Laptyns'kyi, and K. Kenzhebaev; the obtained results are presented in monograph. Complex classes of resonance boundary-value problems whose linear pan cannot be described by Fredholm operators of index zero were investigated by Samoilenko, together with O. A. Boichuk and V. F. Zhuravlev, in monographs. The monograph of Samoilenko and Yu. V. Teplins'kyi