ISBN-13: 9781032017259 / Angielski / Twarda / 2021 / 210 str.
ISBN-13: 9781032017259 / Angielski / Twarda / 2021 / 210 str.
This book focuses on an old problem of the qualitative theory of differential equations, called the Center and Focus Problem. The book reflects the results obtained by the authors in the last decades.