Title: Galois Theory of Difference Equations / Edition 1, Author: Marius van der Put
Title: Asymptotics of Analytic Difference Equations / Edition 1, Author: G. K. Immink
Title: Analytic Theory of the Harish-Chandra C-Function / Edition 1, Author: L. Cohn
Title: Norm Inequalities for Derivatives and Differences / Edition 1, Author: Man K. Kwong