The book "Operational amplifiers and their application: A textbook" under the authorship of a team of authors, including I. P. Efimova, is an indispensable resource for students, graduate students and specialists in the field of electronics and radio engineering . Published in 2000 at Ulyanovsk State Technical University, this work covers key aspects of the design and use of operational amplifiers, which are the main elements in modern electronic devices. From the first pages of the reader plunges into the world of analog electronics, where operational amplifiers occupy a central place. The book begins with the basics of the theory, explaining the principles of these devices, their characteristics and basic parameters. The authors not only describe how operational amplifiers function, but also consider their use in various circuits and devices. The reader will be able to learn about such important topics as inverting and non-inverting schemes, filters, comparators and other key applications, which makes this manual especially valuable for those who want to deepen their knowledge in the field of analog systems design. This book will be of interest not only to students of technical specialties, but also to practicing engineers who are looking for a reliable source of information about modern methods of working with operational amplifiers. It will be useful for those who are engaged in the development of audio systems, measuring instruments, as well as for specialists working in the field of automation and control. The age category of readers varies from high school students interested in electronics to experienced professionals seeking to update their knowledge. The topics raised in the book go beyond purely technical aspects. The authors emphasize the importance of understanding theory and practice in the context of modern technologies, which allows the reader not only to master the material, but also to apply it in real projects. The book also touches on design issues, making it relevant for those who want to not only use ready-made solutions, but also develop their own. The style of presentation of the authors is clear and accessible, which makes it easy to assimilate even the most complex concepts. Each section is accompanied by examples and practical tasks, which contributes to a deeper understanding of the material. In addition, the book presents various diagrams and illustrations that help to visualize the processes and devices described. In addition, and . P. Efimov and his colleagues not only focused on operational amplifiers, but also touched on related topics, such as analog filters and signal processing schemes. This makes the manual multifunctional and useful for a wide range of readers interested in electronics and its applications. If you are looking for a tutorial that will help you understand the operating amplifiers and their application, this publication will be a real find for you. It will not only deepen your knowledge, but also inspire new ideas and projects in the world of electronics. The book “Operational amplifiers and their application” is not just a textbook, but a real guiding star for everyone who wants to become an expert in the field of analog electronics.