This book provides a brisk, thorough treatment of the foundations of algebraic number theory on which it builds to introduce more advanced topics. Throughout, the authors emphasize the systematic development of techniques for the explicit calculation of the basic invariants such as rings of integers, class groups, and units, combining at each stage theory with explicit computations.
THIS BOOK IS AWFUL. It is totally scattered requiring the reader to jump between chapters to pick up relevant notions. The book does not motivate any of its results and the individual chapters are more like outlines.