The book "Global Sourcing" by Gerhard Trautmann offers an in-depth analysis of the strategies and challenges associated with global procurement in multinational companies. In an era of increasing competition, it is crucial for companies to leverage global sourcing synergies. Trautmann examines how organizations can navigate the balance between central control and local flexibility. The book is divided into three main essays that illuminate different aspects of global sourcing. The first essay provides a comprehensive framework for analyzing integration mechanisms in hybrid purchasing organizations. The second essay focuses on portfolio management in global procurement. The third essay analyzes the implementation of global integration for different categories of goods and explains the empirical findings through an information processing model. This thorough investigation is of great interest to professionals and students in the fields of business and law.