Title: Iterative Functional Equations, Author: Marek Kuczma
Title: Functional Equations And Inequalities In Several Variables, Author: Stefan Czerwik
Title: Volterra Integral and Functional Equations, Author: G. Gripenberg
Title: Functional Equations And Inequalities: Solutions And Stability Results, Author: John Michael Rassias
Title: Introduction to Functional Differential Equations / Edition 1, Author: Jack K. Hale
Title: Functional Differential Equations: Advances and Applications / Edition 1, Author: Constantin Corduneanu
Title: Functional Equations in Several Variables, Author: J. Aczel
Title: Functional Equations - Results and Advances / Edition 1, Author: Zoltan Daroczy
Title: Functional Equations, Inequalities and Applications / Edition 1, Author: Themistocles RASSIAS