Book excerpt: Advances in X-Ray Spectroscopy covers topics relevant to the advancement of X-ray spectroscopy technology. The book is a collection of papers written by specialists in X-ray spectroscopy and pays tribute to the scientific work of Prof. Yvette Cauchois. The text is organized into four parts. Part I covers the analysis of X-ray transitions between atomic levels and relativistic theories of X-ray emission satellites and electron BremsStrahlung. Part II reviews the means provided by X-ray spectroscopy for the determination of the electronic structure of solids, while Part III discusses methods of obtaining types of information from X-ray spectra. The fourth part discusses techniques available for studies in the field. Researchers and professionals dealing with X-ray technology will find this book a great source of information regarding its development.