From the reviews of the first edition: "This book treats a family of Dirichlet series in several variables associated with positive definite quadratic forms ... . The purpose of the book under review is to give a crisp version of this theory. ... all of the necessary reduction theory and harmonic analysis is developed simply and efficiently. Although some of the details are, by nature, intricate, this book reduces these to a minimum and provides an accessible account to this important and beautiful area of mathematics." (Samuel James Patterson, Zentralblatt MATH, Vol. 1076, 2006)

• GLn (R) actions on Posn(R).- Measures, Integration, and Quadratic Model.- Special Functions on Posn(R).- Invariant Differential Operators on Posn(R).- Poisson duality and zeta functions.- Eisenstein Series: First Part.- Geometric and Analytic Estimates.- Eisenstein Series: Second Part.