The book "Implementation of an Electronic Invoice Solution using BizTalk SOA" by Bruno Gouveia offers a comprehensive analysis of the implementation of electronic invoices in Portugal, starting with the national initiative from 1998. It highlights the development of electronic trading practices and the associated legal frameworks, particularly the EU Directive 2001/115/EC, which aims to optimize processes. The author examines the standards and formats recommended for the transmission, storage, and security of commercial documents. By utilizing Microsoft's BizTalk Server, it demonstrates how this technology can cover all aspects of electronic invoicing, including integration with existing systems and compliance with security requirements. The book is aimed at professionals and students who wish to gain a deeper understanding of the implementation of electronic invoices and the underlying technology.