This concise text for advanced undergraduates and graduate students covers eigenvalue problems in classical physics, orthogonal functions and expansions, the St... » 

This concise text for advanced undergraduates and graduate students covers eigenvalue problems in classical physics, orthogonal functions and expansions, the Sturm-Liouville theory and linear operators on functions, and linear vector spaces. It emphasizes the unity of a variety of techniques and is enduringly relevant to many physical systems. 1962 edition. «