The book “Ordinary Differential Equations” by Lev Pontryagin is not just a textbook, but a real find for everyone who seeks to better understand the world of mathematical analysis and its applications. Pontryagin, an outstanding Soviet mathematician, left a significant mark in the theory of differential equations, and his work on this topic is one of the most authoritative and popular in the scientific literature. From the first pages of the book, the reader plunges into the fascinating world of mathematical models that describe the dynamics of various processes, from mechanics to biology. Pontryagin masterfully explains how ordinary differential equations can be used to describe real-world phenomena such as body motion, oscillations, wave propagation, and even economic models. Each section of the book is permeated with the spirit of scientific search and the desire for clarity, which makes the material accessible to perception. This book will be of interest not only to students and graduate students of mathematical and physical specialties, but also to anyone who wants to expand their knowledge in the field of applied mathematics. If you study at the Faculty of Mathematics, Physics, Engineering or even Economics, “Ordinary Differential Equations” will be an indispensable tool for you. It is suitable both for self-study and for use as training material in courses. The topics raised in the book cover a wide range of issues, from the foundations of differential equations theory to more complex concepts such as decision stability and qualitative analysis. Pontryagin not only outlines the theory, but also offers many examples and tasks that will help the reader to consolidate the knowledge gained. His approach to explaining complex concepts is clear and logical, which allows even novice researchers to confidently navigate the material. Pontryagin's style can be described as strict, but at the same time accessible. He skillfully combines formal mathematical calculations with intuitive explanations, which makes his work unique in its kind. Pontryagin is also known for his other works, such as The Course in Mathematical Analysis and The Theory of Functions of Complex Variables, which also deserve attention and study. These books, like Ordinary Differential Equations, are distinguished by a high level of scientific rigor and depth of presentation. The book not only enriches the reader with knowledge, but also inspires further research. It raises important questions about how mathematics can be used to solve practical problems, and shows that even the most abstract theories can find application in the real world. The reader, plunging into the pages of Pontryagin, begins to realize that mathematics is not just a set of formulas, but a powerful tool for understanding and describing the surrounding reality. If you’re looking for literature in mathematics that combines theoretical depth and practical utility, Lev Pontryagin’s Ordinary Differential Equations is exactly what you need. This book will be a reliable companion on your way to mastering complex mathematical concepts and will help you discover the amazing world of ordinary differential equations.