Neilson Dunford,Jacob T. Schwartz
This set features: "Linear Operators, Part 1, General Theory" (978-0-471-60848-6), "Linear Operators, Part 2, Spectral Theory, Self Adjoint Operators in Hilbert Space" (978-0-471-60847-9), and "Linear Operators, Part 3, Spectral Operators" (978-0-471-60846-2), all by Neilson Dunford and Jacob T. Schwartz.
Linear Operators, 3-Volume Set