From the reviews of the first edition:

„The volume contains the results of the research covered by the Ph. D. dissertation of Elisa Quintarelli at the Politecnico di Milano. Two specific problems in the area of representation of semistructured data and queries are addressed … . The thesis presents research containing novel contributions and an in-depth expertise on several topics. It represents a valuable source of information.“ (Antonín Ríha, Zentralblatt MATH, Vol. 1069, 2005)