Theory of Functions of a Complex Variable . Operating Calculus" by the authors and. N. Melnikova and N. About. Fastovets is an outstanding work that will become an indispensable assistant for students, graduate students and anyone interested in mathematics and its applications in various fields of science and technology. This work is an in-depth and comprehensive study of the theory of functions of complex variables, as well as of operational calculus, making it an important contribution to modern mathematical literature. The book discusses the basic concepts and methods associated with complex functions, including their properties, analytical functions, integrals and series. The authors pay special attention to operational calculus, which is a powerful tool for solving various mathematical problems. This makes the book relevant not only for theorists, but also for practitioners working in engineering and scientific fields where the application of complex analysis is required. Readers who are already familiar with mathematical analysis and linear algebra will find in this work many useful ideas and methods that can be applied in practice. The book will be of interest to both senior students of mathematical and technical specialties, and teachers who want to deepen their knowledge in the field of complex analysis. It can also attract the attention of researchers involved in mathematical modeling and theoretical physics. The topics raised in the book cover a wide range of issues, ranging from the basics of complex analysis to more complex concepts such as resolvents and transformations. The authors seek not only to explain the theoretical aspects, but also to show their practical application, which makes the material more accessible and understandable. The book contains many examples and tasks that will help the reader to consolidate the knowledge gained and develop skills in working with complex functions. The style of writing of the authors is distinguished by clarity and logical presentation, which makes it easy to assimilate even the most complex topics. and . N. Melnikov and N. About. Fastovets are experienced teachers and researchers who have already established themselves in the scientific community. Their previous work is also devoted to mathematics and its applications, which confirms the high level of their expertise and deep understanding of the subject. Theory of Functions of a Complex Variable . Operational calculus" is not just a textbook, but a real encyclopedia of knowledge on complex analysis. It will become a reliable companion for all who seek a deep understanding of mathematics and its capabilities. Readers interested in topics such as mathematical analysis, differential equations, theoretical physics and engineering sciences will find in this work a lot of useful information and inspiration for further research. If you are looking for a quality and deep tutorial on the theory of functions of a complex variable, then this book is exactly what you need. Do not miss the opportunity to immerse yourself in the world of complex analysis and discover new horizons in mathematics and its applications.